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  • Cobbler 2.2.2 problems

    - by Peter
    I have setup a dedicated LAN for Cobbler tests. My setup is: Cobbler server: openSUSE 12.3, cobbler 2.2.2 (from openSUSE repos) Imported distros: Centos 6.5, Red Hat 6.5, Red Hat 7.0, openSUSE 13.1 Target Machine: VMs in a Windows 7 Virtualbox Systems provisioning works OK, but I have some problems. The first one is that cobbler does not honor the "pxe_just_once: 1" setting. When the setup of the target OS is finished, after the reboot the target systems continues to PXE boot! The second problem is that the target server is not correctly configured! See my setup: cobbler system report --name=test Name : test TFTP Boot Files : {} Comment : Fetchable Files : {} Gateway : 192.168.0.1 Hostname : testcob1.example.com Image : IPv6 Autoconfiguration : False IPv6 Default Device : Kernel Options : {} Kernel Options (Post Install) : {} Kickstart : <<inherit>> Kickstart Metadata : {} LDAP Enabled : False LDAP Management Type : authconfig Management Classes : [] Management Parameters : <<inherit>> Monit Enabled : False Name Servers : ['192.168.0.1', '8.8.8.8'] Name Servers Search Path : [] Netboot Enabled : False Owners : ['admin'] Power Management Address : Power ID : Power Password : Power Management Type : ipmitool Power Username : Profile : RHEL-6.5-x86_64 Proxy : <<inherit>> Red Hat Management Key : <<inherit>> Red Hat Management Server : <<inherit>> Repos Enabled : False Server Override : <<inherit>> Status : testing Template Files : {} Virt Auto Boot : <<inherit>> Virt CPUs : <<inherit>> Virt Disk Driver Type : <<inherit>> Virt File Size(GB) : <<inherit>> Virt Path : <<inherit>> Virt RAM (MB) : <<inherit>> Virt Type : <<inherit>> Interface ===== : eth0 Bonding Opts : Bridge Opts : DHCP Tag : DNS Name : Master Interface : Interface Type : IP Address : 192.168.0.200 IPv6 Address : IPv6 Default Gateway : IPv6 MTU : IPv6 Secondaries : [] IPv6 Static Routes : [] MAC Address : Management Interface : True MTU : Subnet Mask : 255.255.255.0 Static : True Static Routes : [] Virt Bridge : So, although I have setup the hostname and the network interface of the target system, after the setup, the hostname is set to localhost.localdomain and eth0 is configured as a DHCP not static! How can I find the problem and fix it? Note that I have synced and restarted cobbler a couple of times, but the problems persists.

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  • XCP Project Kronos syslog error: "irq ... : nobody cared" on Dom0 host

    - by Vlad Fedin
    One of our production clusters driven by XCP suddenly went uresponsive. After restart and some investigation we found such logs in dom0 machine syslog: Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659040] irq 339: nobody cared (try booting with the "irqpoll" option) Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659058] Pid: 0, comm: swapper/3 Tainted: G C O 3.2.0-24-generic #37-Ubuntu Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659060] Call Trace: Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659062] <IRQ> [<ffffffff810db37d>] __report_bad_irq+0x3d/0xe0 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659071] [<ffffffff810db605>] note_interrupt+0x135/0x190 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659074] [<ffffffff810d8e69>] handle_irq_event_percpu+0xa9/0x220 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659078] [<ffffffff8130ff3b>] ? radix_tree_lookup+0xb/0x10 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659081] [<ffffffff810d9031>] handle_irq_event+0x51/0x80 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659084] [<ffffffff810dc187>] handle_edge_irq+0x87/0x140 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659089] [<ffffffff813a8829>] __xen_evtchn_do_upcall+0x199/0x250 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659092] [<ffffffff813aa96f>] xen_evtchn_do_upcall+0x2f/0x50 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659096] [<ffffffff81666d3e>] xen_do_hypervisor_callback+0x1e/0x30 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659097] <EOI> [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659104] [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659107] [<ffffffff8100a1d0>] ? xen_safe_halt+0x10/0x20 Oct 26 20:32:03 hetzner-2-mrx kernel: [1797931.659110] [<fff IRQ 339 in cat /proc/interrupts: 339: ... xen-pirq-msi-x eth0 where eth0 is hardware NIC. While host machine seems to hang, guest machines continue to work, so our tiny internal monitoring on one of the virtual hosts logged something like that: [2012-10-26 20:31:51] [OK......] 200 OK : 113159149 ns [2012-10-26 20:32:40] [DISASTER] 500 Can't connect to [hostname]:80 (No route to host) : 47763284432 ns ... [2012-10-26 20:34:40] [DISASTER] 500 Can't connect to [hostname]:80 (No route to host) : 46894835070 ns [2012-10-26 20:34:57] [DISASTER] 500 Can't connect to [hostname]:80 (Bad hostname) : 16821741955 ns ... [2012-10-26 20:38:18] [DISASTER] 500 Can't connect to [hostname]:80 (Bad hostname) : 20103298289 ns [2012-10-26 20:38:37] [DISASTER] 500 Can't connect to [hostname]:80 (Bad hostname) : 17895754943 ns Host and guest OS: Ubuntu 12.04 LTS, 05:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection Subsystem: ASUSTeK Computer Inc. Device 8369 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx+ Latency: 0, Cache Line Size: 64 bytes Interrupt: pin A routed to IRQ 17 Region 0: Memory at fe500000 (32-bit, non-prefetchable) [size=128K] Region 2: I/O ports at e000 [size=32] Region 3: Memory at fe520000 (32-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: e1000e Kernel modules: e1000e Any hints how to debug this?

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  • New Exchange 2010 CAS cannot find domain controllers

    - by NorbyTheGeek
    I am experiencing problems migrating from Exchange 2003 to Exchange 2010. I am on the first step: installing a new 2010 Client Access Server role. The Active Directory domain functional level is 2003. All domain controllers are 2003 R2. The only existing Exchange 2003 server happens to be housed on one of the domain controllers. It is running Exchange 2003 Standard w/ SP2. IPv6 is enabled and working on all domain controllers, servers, and routers, including this new Exchange server. After installing the CAS role on a new 2008 R2 server (Hyper-V VM) I am receiving 2114 Events: Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=1600). Topology discovery failed, error 0x80040a02 (DSC_E_NO_SUITABLE_CDC). Look up the Lightweight Directory Access Protocol (LDAP) error code specified in the event description. To do this, use Microsoft Knowledge Base article 218185, "Microsoft LDAP Error Codes." Use the information in that article to learn more about the cause and resolution to this error. Use the Ping or PathPing command-line tools to test network connectivity to local domain controllers. Prior to each, I receive the following 2080 Event: Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=1600). Exchange Active Directory Provider has discovered the following servers with the following characteristics: (Server name | Roles | Enabled | Reachability | Synchronized | GC capable | PDC | SACL right | Critical Data | Netlogon | OS Version) In-site: b.company.intranet CDG 1 0 0 1 0 0 0 0 0 s.company.intranet CDG 1 0 0 1 0 0 0 0 0 Out-of-site: a.company.intranet CD- 1 0 0 0 0 0 0 0 0 o.company.intranet CD- 1 0 0 0 0 0 0 0 0 g.company.intranet CD- 1 0 0 0 0 0 0 0 0 Connectivity between the new Exchange server and all domain controllers via IPv4 and IPv6 are all working. I have verified that the new Exchange server is a member of the following groups: Exchange Servers Exchange Domain Servers Exchange Install Domain Servers Exchange Trusted Subsystem Heck, I even put the new Exchange server into Domain Admins just to see if it would help. It didn't. I can't find any evidence of Active Directory replication problems, all pre-setup Setup tasks (/PrepareLegacyExchangePermissions, /PrepareSchema, /PrepareAD, /PrepareDomain) completed successfully. The only problem so far that I haven't been able to resolve with my Active Directory is I am unable to get my IPv6 subnets into Sites and Services Where should I proceed from here?

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  • networked storage for a research group, 10-100 TB

    - by Marc
    this is related to this post: http://serverfault.com/questions/80854/scalable-24-tb-nas-for-research-department but perhaps a little more general. Background: We're a research lab of around 10 people who do a lot of experiments that involve taking pictures at one of several lab setups and then analyzing it an one of several lab computers. Each experiment may produce 2 or 3 GB of data, and we are generating data at the rate of about 10 TB/year. Right now, we are storing the data on a 6-bay netgear readynas pro, but even with 2 TB drive, this only gives us 10 TB of storage. Also, right now we are not backing up at all. Our short term backup plan is to get a second readynas, put it in a different building and mirror the one drive onto the other. Obviously, this is somewhat non-ideal. Our options: 1) We can pay our university $400/ TB /year for "backed up" online storage. We trust them more than we trust us, but not a whole lot. 2) We can continue to buy small NASs and mirror them between offices. One limit, although stupid, is that we don't have an unlimited number of ethernet jacks. 3) We can try to implement our own data storage solution, which is why I'm asking you guys. One thing to consider is that we're a very transient population and none of us are network administration experts. I will probably be here only another year or so, and graduate students, who are here the longest, have a 5-6 year time scale. So nothing can require expert oversight. Our data transfer rates are low - most of the data will just sit on the server waiting for someone to look at it once or twice - so we don't need a really high speed system. Given these contraints, can someone recommend a fairly low-cost, scalable, more or less turn key shared data storage system with backup in a separate physical location. Does such a thing exist or should we just pay the university to take care of it for us? As a second question, our professor just got tenure and is putting together a budget. Here the goal is to ask for as much as you can and hope you get a fraction of it. So the same question, minus the low-cost. Without budget constraints, can you recommend a scalable turn-key backed up storage system. Thanks

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  • What's the best scenario for using a wireless router with Comcast Business Class

    - by Buck
    Just had Comcast Business Class internet installed (usage details at bottom of post). During the call to order I asked about the hardware they'd be providing and was told it was a docsis 3 modem that I'd have to pay $7.00/month for. Figuring I'd have to buy a router anyway, I decided to get my own modem - a Surfboard SB6121 Docsis 3. I called in to tech support to ask some questions and learned that the modem they would have provided DID have a router built in. It's an SMCD3G-CCR. It's not wireless (we need wireless). The guy explained that it was better to have their hardware here because if there's a problem with our service and we're using our own hardware, chances are they'll blame it on our hardware and do nothing since they don't support it. He explained that I could still hang my own wireless router off their modem/router and if we ever had any service problems, we'd be able to plug directly into their hardware and they'd be able to tell where the problem is and they wouldn't be able to pawn it off onto "customer provided equipment". That all said, a few questions: 1. Am I better off returning my Surfboard modem and getting the Comcast one? If I get a wireless router and plug into one of the ethernet ports of the Comcast device, should I NOT plug anything else into the Comcast device since it would be a different network from anything connecting via the wireless router? Is that correct? Given that I know VERY LITTLE about networking and setting up hardware like this... since I need wireless and will HAVE to get a wireless router to work with this Comcast device, do I need to do anything with the settings of the Comcast device? Do I use security on the Comcast device or the wireless router or both? Any suggestions or anything I need to think about, given this scenario, in order to use a business-type voip service like RingCentral or Jive or Nextiva? Any recommendations on a wireless router for this scenario? We are running 2 PCs (possibly 3-4 in the future) - could be wired for the time being if needed but would prefer wireless; would like to have a networked hard drive and a networked printer; NEED business-type VOIP service asap for 2 phone lines. Would like to hook up some IP cameras at some point (but not the kind that require static IPs since I don't have one nor do I plan to pay Comcast another $15/month for one). I don't have or plan to have any type of web servers or anything like that. Want to use WPA or WPA2 security and take advantage of the NAT feature of the router for additional protection (that's the extent of my networking knowledge).

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  • Windows Server 2008 - one MAC Address, assign multiple external IP's to VirtualBoxes running as guests on host

    - by Sise
    Couldn't find any help @ google or here. The scenario: Windows Server 2008 Std x64 on i7-975, 12 GB RAM. The server is running in a data centre. One hardware NIC - RealTek PCIe GBE - one MAC Address. The data centre provides us 4 static external IP's. The first is assigned to the host by default of course. I have ordered all 4 IP's, the data centre can assign the available IP's to the physical MAC address of the given NIC only. This means one NIC, one MAC Address, 4 IP's. Everything works fine so far. Now, what I would like to have: Installed VirtualBox with 1-3 guests running, each gets it's own external IP assigned. Each of it should be an standalone Win Server 2008. It looks like the easiest way would be to put the guests into an virtual subnet and routing all data coming to the 2nd till 4th external IP through to this guests using there subnet IP's. I have been through the VirtualBox User Manuel regarding networking. What's not working: I can't use bridged networking without anything else, because the IP's are assigned to the one MAC address only. I can't use NAT networking because it does not allow access from outside or the host to the guest. I do not wanna use port forwarding. Host-only networking itself would not allow internet access, by sharing the default internet connection of the host, internet is granted from the guest to the outside but not from outside or the host to the guest. InternalNetworking is not really an option here. What I have tried is to create an additional MS Loopback adapter for a routed subnet, where the Vbox guests are in, now the idea was to NAT the internet connection to the loopback 'subnet'. But I can't ping the gateway from the guests. By using route command in the command shell or RRAS (static route, NAT) I didn't get there as well. Solutions like the following do work for the one way, but not for the way back: For your situation, it might be best to use the Host-Only adapter for ICS. Go to the preferences of VB itself and select network. There you can change the configuration for the interface. Set the IP address to 192.168.0.1, netmask 255.255.255.0. Disable the DHCP server if it isn't already and that's it. Now the Guest should get an IP from Windows itself and be able to get onto the internet, while you can also access the Host. Slowly I'm pretty stucked with this topic. There is a possibility I've just overlooked something or just didn't getting it by trying, especially using RRAS, but it's kinda hard to find useful howto's or something in the web. Thanks in advance! Best regards, Simon

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  • Some emails are being delivered, some returned

    - by Tom Broucke
    I have my own VPS where a site is running (control panel: directadmin). When I send mails, some are being delivered (hotmail, gmail, [email protected] ,...), others are not ([email protected]), others are delivered after being greylisted ([email protected]). /var/log/exim/mainlog What could be the cause of this? Is the problem Sender-Side or Receiver-Side? case 1: [email protected] (delivered) 2012-06-20 15:02:03 1ShKXr-0005Sc-7g <= [email protected] U=apache P=local S=1319 T="Password reset" from <[email protected]> for [email protected] 2012-06-20 15:02:03 1ShKXr-0005Sc-7g gmail-smtp-in-v4v6.l.google.com [2a00:1450:8005::1b] Network is unreachable 2012-06-20 15:02:03 1ShKXr-0005Sc-7g => [email protected] F=<[email protected]> R=lookuphost T=remote_smtp S=1355 H=gmail-smtp-in-v4v6.l.google.com [173.194.67.27] X=TLSv1:RC4-SHA:128 C="250 2.0.0 OK 1340196103 cp4si34336466wib.14" 2012-06-20 15:02:03 1ShKXr-0005Sc-7g Completed case 2: [email protected] (not being delivered) 2012-06-21 09:57:14 1ShcGQ-0007No-5H <= [email protected] H=localhost ([91.230.245.141]) [127.0.0.1] P=esmtpa A=login:[email protected] S=740 [email protected] T="hey" from <[email protected]> for [email protected] 2012-06-21 09:57:14 1ShcGQ-0007No-5H ** [email protected] F=<[email protected]> R=virtual_aliases: 2012-06-21 09:57:14 1ShcGQ-0007Nt-7Z <= <> R=1ShcGQ-0007No-5H U=mail P=local S=1546 T="Mail delivery failed: returning message to sender" from <> for [email protected] 2012-06-21 09:57:14 1ShcGQ-0007No-5H Completed 2012-06-21 09:57:14 1ShcGQ-0007Nt-7Z => info <[email protected]> F=<> R=virtual_user T=virtual_localdelivery S=1643 2012-06-21 09:57:14 1ShcGQ-0007Nt-7Z Completed case 3: [email protected] (greylisted) 2012-06-21 15:29:02 1ShhRW-000862-BV <= [email protected] H=localhost ([91.230.245.141]) [127.0.0.1] P=esmtpa A=login:[email protected] S=782 [email protected] T="testmail squirrel" from <[email protected]> for [email protected] 2012-06-21 15:29:02 1ShhRW-000862-BV SMTP error from remote mail server after RCPT TO:<[email protected]>: host mx-cluster-b1.one.com [195.47.247.194]: 450 4.7.1 <[email protected]>: Recipient address rejected: Greylisted for 5 minutes 2012-06-21 15:29:02 1ShhRW-000862-BV == [email protected] R=lookuphost T=remote_smtp defer (-44): SMTP error from remote mail server after RCPT TO:<[email protected]>: host mx-cluster-b2.one.com [195.47.247.195]: 450 4.7.1 <[email protected]>: Recipient address rejected: Greylisted for 5 minutes Notice that the "from" in case1 differs in case2: [email protected] or [email protected]. Thanks for your time!

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  • VMware server 2.0 SYN/ACK repeating issues

    - by user65579
    VMWare Server 2.0.0 Build 122956 I am having some issues with connecting into a guest VM (Ubuntu linux 4.4.3-4 lucid) running under VMware 2.0 on a windows server host. All connections to and from the VM's work fine, except for FTP. I thought the issue was the FTP daemon at first but it has been ruled out that it is not the daemon or the server itself. When you try to connect to the FTP server from outside of the host OS it fails with a "421 Service not available" but when you try and connect from the local VM or from the host OS the connection goes through fine. I have ran many packet sniffs using wireshark/tcpdump from the VM, the host OS, and the client connecting, the most informative is the host OS. I have attached a PNG of the relavant packets that were captured. I viewed some other network traffic that was sniffed (WWW specifically) and it seems to do the same syn/ack repeating but the user doesnt see any issues. I have disabled the firewall and the issues persisits, I have tried with specific allow rules to ensure the data is allowed and no changes. It appears like VMware attempts to do the ICMP redirect and it works, but then it vmware repeats the packets sent so you get 3 syn/ack's for every one syn from the client. Also VMWare appears to be attempting to establish an FTP connection between the HOST OS and the GUEST OS, because I see the second SYN sent from the HOST OS to the GUEST to initiate a new connection, and it get the appropriate SYN/ACK followed by an ACK, but the client never sees any of this from its end. EG. syn from client syn/ack from host OS to client syn/ack from guest OS to client syn/ack from host OS to client The same thing happens when the connection reset is attempted, RST's start being sent and repeated, the server responds with a valid header to continue the FTP handshake but the RST acknowledgement is allready issued and things are closed. I am not 100% if this is a bug in VMware or possibly a VMNetwork missconfiguration. Does anyone have any thoughts on where exactly the issue could be, things to try to verify or rule out? I have linked to a picture of the relevant packets sniffed from the host OS. http://img18.imageshack.us/img18/7789/vmwareftpconnection.jpg

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  • Ubuntu 11.10 firewall/gateway - no client internet access

    - by Siriss
    I have read many other posts but cannot figure this out. eth0 is my external connected to a Comcast modem. The server has internet access with no issues. eth1 is internal and running DHCP for the clients. I have DHCP working just fine, all my clients can get an IP and ping the server but they cannot access the internet. I am using ISC-DHCP-SERVER and have set /etc/default/isc-dhcp-server to INTERFACE="eht1" Here is my dhcpd.conf file located in /etc/dhcp/dhcpd.conf ddns-update-style interim; ignore client-updates; subnet 10.0.10.0 netmask 255.255.255.0 { range 10.0.10.10 10.0.10.200; option routers 10.0.10.2; option subnet-mask 255.255.255.0; option domain-name-servers 208.67.222.222, 208.67.220.220; #OpenDNS # option domain-name "example.com"; default-lease-time 21600; max-lease-time 43200; authoritative; } I have made the *net.ipv4.ip_forward=1* change in /etc/sysctl.conf here is my interfaces file: auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp iface eth1 inet static address 10.0.10.2 netmask 255.255.255.0 network 10.0.10.0 auto eth1 And finally- here is my iptables.conf file: # Firewall configuration written by system-config-firewall # Manual customization of this file is not recommended. *nat :PREROUTING ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] -A POSTROUTING -s 10.0.10.0/24 -o eth0 -j MASQUERADE #-A PREROUTING -i eth0 -p tcp --dport 59668 -j DNAT --to-destination 10.0.10.2:59668 COMMIT *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT -A INPUT -p icmp -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -i eth1 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 443 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 53 -j ACCEPT -A INPUT -m state --state NEW -m udp -p udp --dport 53 -j ACCEPT -A FORWARD -s 10.0.10.0/24 -o eth0 -j ACCEPT -A FORWARD -d 10.0.10.0/24 -m state --state ESTABLISHED,RELATED -i eth0 -j ACCEPT -A FORWARD -p icmp -j ACCEPT -A FORWARD -i lo -j ACCEPT -A FORWARD -i eth1 -j ACCEPT #-A FORWARD -i eth0 -m state --state NEW -m tcp -p tcp -d 10.0.10.2 --dport 59668 -j ACCEPT -A INPUT -j REJECT --reject-with icmp-host-prohibited -A FORWARD -j REJECT --reject-with icmp-host-prohibited COMMIT I am completely stuck. I cannot figure out why the clients cannot access the internet. Am I missing a service? Is a service not running? Any help would be greatly appreciated. I tried to be as thorough as possible but please let me know if I have missed something. Thank you!

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  • Reasons for missing IP info in `last` output on pts logins?

    - by Mike Pennington
    I have five CentOS 6 linux systems at work, and encountered a rather strange issue that only seems to happen with my userid across all the linux systems I have... This is an example of the problem from entries I excepted from the last command... mpenning pts/19 Fri Nov 16 10:32 - 10:35 (00:03) mpenning pts/17 Fri Nov 16 10:21 - 10:42 (00:21) bill pts/15 sol-bill.local Fri Nov 16 10:19 - 10:36 (00:16) mpenning pts/1 192.0.2.91 Fri Nov 16 10:17 - 10:49 (12+00:31) kkim14 pts/14 192.0.2.225 Thu Nov 15 18:02 - 15:17 (4+21:15) gduarte pts/10 192.0.2.135 Thu Nov 15 12:33 - 08:10 (11+19:36) gduarte pts/9 192.0.2.135 Thu Nov 15 12:31 - 08:10 (11+19:38) kkim14 pts/0 :0.0 Thu Nov 15 12:27 - 15:17 (5+02:49) gduarte pts/6 192.0.2.135 Thu Nov 15 11:44 - 08:10 (11+20:25) kkim14 pts/13 192.0.2.225 Thu Nov 15 09:56 - 15:17 (5+05:20) kkim14 pts/12 192.0.2.225 Thu Nov 15 08:28 - 15:17 (5+06:49) kkim14 pts/11 192.0.2.225 Thu Nov 15 08:26 - 15:17 (5+06:50) dspencer pts/8 192.0.2.130 Wed Nov 14 18:24 still logged in mpenning pts/18 alpha-console-1. Mon Nov 12 14:41 - 14:46 (00:04) You can see two of my pts login entries above that do not have a source IP address associated with them. My CentOS machines have as many as six other users that share the systems, but the mpenning userid is the only one that has this issue. Approximately 5% of my logins see this issue, but no other usernames exhibit this behavior. Questions Given the kind of scripts I keep on these systems (which control much of our network infrastructure), I'm a little spooked by this and would like to understand what would cause my logins to occasionally miss source addresses. Is there anything (other than malicious activity) that would reasonably explain the behavior? Other than bash history timestamping, are there other things I can do to track the issue down? Informational Since this started happening, I enabled bash history time-stamping (i.e. HISTTIMEFORMAT="%y-%m-%d %T " in .bash_profile) and also added a few other bash history hacks; however, that does not give clues to what happened during the previous occurrences. All the systems run CentOS 6.3... [mpenning@typo ~]$ uname -a Linux typo.local 2.6.32-279.9.1.el6.x86_64 #1 SMP Tue Sep 25 21:43:11 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux [mpenning@typo ~]$ EDIT If I use last -i mpenning, I see entries like this... mpenning pts/19 0.0.0.0 Fri Nov 16 10:32 - 10:35 (00:03) mpenning pts/17 0.0.0.0 Fri Nov 16 10:21 - 10:42 (00:21)

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  • What the best way to achieve RPO of zero and lowest possible RTO (less than 15 minutes) with SQL 2008 R2?

    - by Adrian Hope-Bailie
    We are running a payments (EFT transaction processing) application which is processing high volumes of transactions 24/7 and are currently investigating a better way of doing DB replication to our disaster recovery site. Our current and previous strategies have included using both DoubleTake and Redgate to replicate data to a warm stand-by. DoubleTake is the supported solution from the payments software vendor however their (DoubleTake's) support in South Africa is very poor. We had a few issues and simply couldn't ever resolve them so we had to give up on DoubleTake. We have been using Redgate to manually read the data from the primary site (via queries) and write to the DR site but this is: A bad solution Getting the software vendor hot and bothered whenever we have support issues as it has a tendency to interfere with the payment application which is very DB intensive. We recently upgraded the whole system to run on SQL 2008 R2 Enterprise which means we should probably be looking at using some of the built-in replication features. The server has 2 fairly large databases with a mixture of tables containing highly volatile transactional data and pretty static configuration data. Replication would be done over a WAN link to a separate physical site and needs to achieve the following objectives. RPO: Zero loss - This is transactional data with financial impact so we can't lose anything. RTO: Tending to zero - The business depends on our ability to process transactions every minute we are down we are losing money I have looked at a few of the other questions/answers but none meet our case exactly: SQL Server 2008 failover strategy - Log shipping or replication? How to achieve the following RTO & RPO with logshipping only using SQL Server? What is the best of two approaches to achieve DB Replication? My current thinking is that we should use mirroring but I am concerned that for RPO:0 we will need to do delayed commits and this could impact the performance of the primary DB which is not an option. Our current DR process is to: Stop incoming traffic to the primary site and allow all in-flight transaction to complete. Allow the replication to DR to complete. Change network routing to route to DR site. Start all applications and services on the secondary site (Ideally we can change this to a warmer stand-by whereby the applications are already running but not processing any transactions). In other words the DR database needs to, as quickly as possible, catch up with primary and be ready for processing as the new primary. We would then need to be able to reverse this when we are ready to switch back. Is there a better option than mirroring (should we be doing log-shipping too) and can anyone suggest other considerations that we should keep in mind?

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  • DNS Issue Windows 2003 AD-The server holding the PDC role is down

    - by Dave M
    Our network of Windows 2003 and Windows 2008 servers suddenly hasDNS issues. There are 7 DCs. Two at our main office and one each at branch sites (one branch has two a 2008R2 and WIN2K3) Only two are WIN2008R2 Running DCDIAG on the WIN2K3 at main site (DC1) reports no issues. Running at any branch site reports two issues All other test pass. The server DC1 can be PINGed by name from any site Starting test: frsevent There are warning or error events within the last 24 hours after the SYSVOL has been shared. Failing SYSVOL replication problems may cause Group Policy problems. Starting test: FsmoCheck Warning: DcGetDcName(PDC_REQUIRED) call failed, error 1355 A Primary Domain Controller could not be located. The server holding the PDC role is down. Netdom.exe /query DC reports the expected servers. netdom query fsmo This reports the server at the main office holds the following roles: * Schema owner Domain role owner PDC role RID pool manager Infrastructure owner In the DNS management snap-in, DC1 appears as DNS server but does not appear in _msdcs-dc-_sites-Default-First-Site-Name-_TCP There is no _ldap or –kerberos record pointing to DC1 Same issue msdcs-dc-_sites- -_TCP Again there is no _ldap or –kerberos record pointing to DC1 Under Domain DNS Zones there is no entry for the server. This is the case for any _tcp folder in the DNS. The server DC1 appears correctly as a name server in the Reverse Lookup Zone. There is a Host(A) record for DC1 but in the Forward Lookup Zone there is no (same as parent folder) Host(A) for the DC1 server but such an entry exists for the other DCs at branch sites and the other DC at the main office. We have tried stopping and starting the netlogon service, restarting DNS and also dcdiag /fix. Netdiag reports error: Trust relationship test. . . . . . : Failed [FATAL] Secure channel to domain 'XXX' is broken. [ERROR_NO_LOGON_SERVERS] [WARNING] Failed to query SPN registration on DC- One entry for each branch DC All braches lsit the problem server and it can be Pinged by name from any branch Fixing is number one priority but also would like to determine the casue.

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  • A proper way to create non-interactive accounts?

    - by AndreyT
    In order to use password-protected file sharing in a basic home network I want to create a number of non-interactive user accounts on a Windows 8 Pro machine in addition to the existing set of interactive accounts. The users that corresponds to those extra accounts will not use this machine interactively, so I don't want their accounts to be available for logon and I don't want their names to appear on welcome screen. In older versions of Windows Pro (up to Windows 7) I did this by first creating the accounts as members of "Users" group, and then including them into "Deny logon locally" list in Local Security Policy settings. This always had the desired effect. However, my question is whether this is the right/best way to do it. The reason I'm asking is that even though this method works in Windows 8 Pro as well, it has one little quirk: interactive users from "User" group are still able to see these extra user names when they go to the Metro screen and hit their own user name in the top-right corner (i.e. open "Sign out/Lock" menu). The command list that drops out contains "Sign out" and "Lock" commands as well as the names of other users (for "switch user" functionality). For some reason that list includes the extra users from "Deny logon locally" list. It is interesting to note that this happens when the current user belongs to "Users" group, but it does not happen when the current user is from "Administrators". For example, let's say I have three accounts on the machine: "Administrator" (from "Administrators", can logon locally), "A" (from "Users", can logon locally), "B" (from "Users", denied logon locally). When "Administrator" is logged in, he can only see user "A" listed in his Metro "Sign out/Lock" menu, i.e. all works as it should. But when user "A" is logged in, he can see both "Administrator" and user "B" in his "Sign out/Lock" menu. Expectedly, in the above example trying to switch from user "A" to user "B" by hitting "B" in the menu does not work: Windows jumps to welcome screen that lists only "Administrator" and "A". Anyway, on the surface this appears to be an interface-level bug in Windows 8. However, I'm wondering if going through "Deny logon locally" setting is the right way to do it in Windows 8. Is there any other way to create a hidden non-interactive user account?

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  • Webserver Responses Hanging

    - by drscroogemcduck
    From some networks requesting certain images on our webserver is very flakey. I've looked at tcpdumps on both sides and the server sends back part of the file and the client ACKs the TCP packet but the server never receives the ACK. The servers view: 41 19.941136 212.169.34.114 209.20.73.85 TCP 52456 > http [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=2 42 19.941136 209.20.73.85 212.169.34.114 TCP http > 52456 [SYN, ACK] Seq=0 Ack=1 Win=5440 Len=0 MSS=1360 46 20.041142 212.169.34.114 209.20.73.85 TCP 52456 > http [ACK] Seq=1 Ack=1 Win=65280 Len=0 47 20.045142 212.169.34.114 209.20.73.85 HTTP GET /map/map/s+74-WBkWk0aR28Yy-YjXA== HTTP/1.1 48 20.045142 209.20.73.85 212.169.34.114 TCP http > 52456 [ACK] Seq=1 Ack=522 Win=6432 Len=0 49 20.045142 209.20.73.85 212.169.34.114 TCP [TCP segment of a reassembled PDU] (Part of the content of the image 2720 bytes. i assume it is reassembled in tcpdump and it is fragmented over the wire.) ** never receives the ACK sent in frame 282 and will eventually resend the tcp segment ** The clients view: 274 26.161773 10.0.16.67 209.20.73.85 TCP 52456 > http [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=2 276 26.262867 209.20.73.85 10.0.16.67 TCP http > 52456 [SYN, ACK] Seq=0 Ack=1 Win=5440 Len=0 MSS=1360 277 26.263255 10.0.16.67 209.20.73.85 TCP 52456 > http [ACK] Seq=1 Ack=1 Win=65280 Len=0 278 26.265193 10.0.16.67 209.20.73.85 HTTP GET /map/map/s+74-WBkWk0aR28Yy-YjXA== HTTP/1.1 279 26.365562 209.20.73.85 10.0.16.67 TCP http > 52456 [ACK] Seq=1 Ack=522 Win=6432 Len=0 280 26.368002 209.20.73.85 10.0.16.67 TCP [TCP segment of a reassembled PDU] (Part of the content of the image. Only 1400 bytes.) 282 26.571380 10.0.16.67 209.20.73.85 TCP 52456 > http [ACK] Seq=522 Ack=1361 Win=65280 Len=0 The network we are having trouble with is NATd. Is there any kind of explanation for this weirdness?

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  • Win-XP Browsers Hang on page load - (waiting for...)

    - by CHarmon
    Hello, I’m having problems with my browsers hanging on loading pages on my desktop machine. I’m using Windows XP Pro with SP3 and fully updated except for IE 8. All three of my browsers, IE 7, Chrome and Firefox are having the same problems. Pages are not being loaded and are hanging on “waiting for …”. The browsers are waiting for the page being loaded or ad servers. Sometimes a page will load but the loading graphic continues to be displayed as if the page were still loading when the page appears to be fully loaded. The problem is bad enough that I can’t really use any of my browsers. I can eventually get most pages to load by stopping and restarting the page load. I have DSL modem with a wireless router and I have been able to eliminate the modem and router from being the source of my problem. My laptop doesn’t have any problems even when hardwired to the router and with the wireless connection disabled. I deleted the NIC and let XP re-install. Also tried a different network cable. Tried the same router port used in the laptop test. One clue that may be important is that I can’t connect to my router using the desktop machine…the page hangs while trying to connect. I can ping the router and I can quickly connect to the router using the laptop. I also can’t use the Windows update process – the page never fully loads. The problem affects other user accounts and even happens in safe mode. I am convinced the problem is with part of the O/S…some layer able to affect all of the browsers. The purpose of this post is to see if anyone has some ideas before I do a XP repair. I have done quite a bit of trouble-shooting: Ran a full anti-virus scan with AVG – no problems. Ran full scans with Spybot, MalwareBytes and Sophos anti-rootkit – no problems. Ran Chkdsk with both options checked. Ran Disk Clean up Defragged RE-installed IE7 Cleared all the browser caches Ran Ccleaner (registry tool) Ran HijackThis – nothing unusual (problem happens in safe mode too) Ran Process Explorer – no unusual processes Used System Restore and fell back several days – no change in the problem Booted to last known good configuration – no change in the problem Ran MicrosoftFixit50199.msi – no change in the problem Any ideas or suggestions would be appreciated…I’m not looking forward to doing a repair on XP. Thanks in advance for any help.

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  • Exchange-Server Query

    - by Rudi Kershaw
    First, a little background. I've recently been taken on as a web and software developer for a small company, who has no other in-house IT support. They've been asking my opinion on lots of IT subjects that are quite far out of my comfort zone. I'm definitely not a network admin. Their IT consultancy contractor is pushing them to upgrade their dedicated exchange server, even though it seems like the one they currently have has a lot of life left in it and is running problem free. They say it's "coming to the natural end of it's life". They want to install a monster with a Xeon E5-2420, 32GB RAM, 2x 1TB HDDs, Windows Server 2012 and Microsoft Exchange 2010. They want to charge a small fortune for it. Basically, this system seems massively over the top seeing as it won't be doing anything else other than running as an exchange server for a company with less than 25 email accounts. My employers also have a file server system in-house that hosts three web apps, an SQL server, their local domain, print server and shared folders. That machine is using the same specs as the proposed new one, and it is barely using any of it's potential. I asked if Microsoft Exchange 2010 could be installed on their file server, but they said that MS Exchange can't run on the same system as an SQL server because for some reason they will eat up each others resources (even though the SQL server isn't touching 1% of the current system's CPU or RAM). My question is really, are they trying to rip my employers off? Could MS Exchange be installed on their other server (on a virtual instance or not), or does the old one even need replacing at all? Going with their current suggestion will cost the company in excess of £6k, and it seems entirely unnecessary. I apologies, because I know this is probably a little thin on details, but if I carry on I could end up writing a massive essay that no-one will want to read. I've been doing my research, but I'm not knowledgeable enough make any hard decisions. Let me know if you need any more details. Thank you for any help you can offer. Further Details: The new exchange would need to support Outlook Web App, 25 users, a few public mailboxes, and email exchange with Blackberries.

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  • Managing hosts and iptables in scalable architecture

    - by hakunin
    Let's say I have a load balancer in front of 3 app servers. Let's say I also have these services available at certain IPs: Postgres server Redis server ElasticSearch server Memcached server 1 Memcached server 2 Memcached server 3 So that's 6 nodes at 6 different IP addresses. Naturally, every one of my 3 app servers needs to talk to these 6 servers above. Then, to make it a bit funkier, I also have 3 worker servers. And each worker also talks to the above 6 servers, but thankfully workers and apps never need to talk to each other. Now's the kicker. Everything is on Digital Ocean VPS. What that means is: you have no private network, no private IPs. You only have separate, random IP address on each machine. You can't mask them or anything. So in order to build a secure environment I would have to configure some iptables. For example: Open app servers be accessed by load balancer server Open redis, ES, PG, and each memcached servers to be accessed by each app's IP and each worker's IP This means that every time I add an app or worker I have to also reconfigure iptables in those above 6 servers to welcome the new app or worker. Is there a way to simplify this type of setup? I was thinking — what if there was a gateway machine between apps/workers and the above 6 machines. This way all the interaction would always happen via the gateway server, and when I add a new app or worker I wouldn't need to teach the 6 servers to let it in. If I went this route, then I'd hope a small 512mb server could handle that perhaps, and there wouldn't be almost any overhead. Or would there? Please help with best way to handle this situation. I would appreciate an answer as concrete as possible. I don't think this is too specific, because this general architecture is very common, and Digital Ocean is becoming increasingly popular. A concrete solution here would be much appreciated by many.

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  • ssh client problem: Connection reset by peer

    - by yonix
    I'm having a really annoying problem on my Ubuntu laptop. I noticed it today, after upgrading to Ubuntu 11.04, although I'm not entirely sure this is the cause as I played with my ssh keys a few days ago. The problem is, whenever I try to ssh to ANY host I get the following error: Read from socket failed: Connection reset by peer running with -vvv gives the following output: OpenSSH_5.8p1 Debian-1ubuntu3, OpenSSL 0.9.8o 01 Jun 2010 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to hostname [10.0.0.2] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/id_rsa type -1 debug1: identity file /root/.ssh/id_rsa-cert type -1 debug1: identity file /root/.ssh/id_dsa type -1 debug1: identity file /root/.ssh/id_dsa-cert type -1 debug1: identity file /root/.ssh/id_ecdsa type -1 debug1: identity file /root/.ssh/id_ecdsa-cert type -1 debug1: Remote protocol version 1.99, remote software version OpenSSH_4.2 debug1: match: OpenSSH_4.2 pat OpenSSH_4* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.8p1 Debian-1ubuntu3 debug2: fd 3 setting O_NONBLOCK debug3: load_hostkeys: loading entries for host "hostname" from file "/root/.ssh/known_hosts" debug3: load_hostkeys: loaded 0 keys debug1: SSH2_MSG_KEXINIT sent Read from socket failed: Connection reset by peer My /etc/ssh/ssh_config: Host * SendEnv LANG LC_* HashKnownHosts yes GSSAPIAuthentication no GSSAPIDelegateCredentials no I can connect to my laptop from any other server via ssh, and I can also ssh localhost from my laptop successfully. I can connect to all these other server from other laptops, and I don't see anything in the logs of the other servers regarding my failed attempt. I tried to stop iptables, didn't help. I tried several tricks I could find online with my /etc/ssh/ssh_config, but I was unsuccessful in solving the problem... Any ideas? Edit: This is the log from one of the hosts I try to connect to: May 1 19:15:23 localhost sshd[2845]: debug1: Forked child 2847. May 1 19:15:23 localhost sshd[2845]: debug3: send_rexec_state: entering fd = 8 config len 577 May 1 19:15:23 localhost sshd[2845]: debug3: ssh_msg_send: type 0 May 1 19:15:23 localhost sshd[2845]: debug3: send_rexec_state: done May 1 19:15:23 localhost sshd[2847]: debug1: rexec start in 5 out 5 newsock 5 pipe 7 sock 8 May 1 19:15:23 localhost sshd[2847]: debug1: inetd sockets after dupping: 3, 3 May 1 19:15:23 localhost sshd[2847]: Connection from 10.0.0.7 port 55747 May 1 19:15:23 localhost sshd[2847]: debug1: Client protocol version 2.0; client software version OpenSSH_5.8p1 Debian-1ubuntu3 May 1 19:15:23 localhost sshd[2847]: debug1: match: OpenSSH_5.8p1 Debian-1ubuntu3 pat OpenSSH* May 1 19:15:23 localhost sshd[2847]: debug1: Enabling compatibility mode for protocol 2.0 May 1 19:15:23 localhost sshd[2847]: debug1: Local version string SSH-2.0-OpenSSH_5.3 May 1 19:15:23 localhost sshd[2847]: debug2: fd 3 setting O_NONBLOCK May 1 19:15:23 localhost sshd[2847]: debug2: Network child is on pid 2848 May 1 19:15:23 localhost sshd[2847]: debug3: preauth child monitor started May 1 19:15:23 localhost sshd[2847]: debug3: mm_request_receive entering May 1 19:15:23 localhost sshd[2848]: debug3: privsep user:group 74:74 May 1 19:15:23 localhost sshd[2848]: debug1: permanently_set_uid: 74/74 May 1 19:15:23 localhost sshd[2848]: debug1: list_hostkey_types: ssh-rsa,ssh-dss May 1 19:15:23 localhost sshd[2848]: debug1: SSH2_MSG_KEXINIT sent May 1 19:15:23 localhost sshd[2848]: debug3: Wrote 784 bytes for a total of 805 May 1 19:15:23 localhost sshd[2848]: fatal: Read from socket failed: Connection reset by peer

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  • Alienware m15x (older model) BSOD investigation

    - by Crishu
    A frined of mine asked me to help him with an Alienware m15x laptop that had a little service history. It was bought in june 2008, serviced in january 2009 for a random fps drop problem, Alienware returned it saying nothing was wrong. The laptop still had hiccups, but after juggling a few drivers and settings, the fps drops weren't as noticeable. Eventually it died in Sept. 2009. It would not boot up locking itself on a white/gray screen. (i think it was overheating .. clocking in 100 degrees Celsius). So back to Alienware it went. They replaced the GPU and all was fine. Up until these blue screens started showing up. One other thing that was updated was the HDD and a Windows 7 reinstall, in August. From then on it seems to have started its BSOD. Could this be the culprit? Why? 0_o The original Windows was Vista but it was upgraded with a digital download/purchase of Windows 7 Home Premium and activated after installing windows. No errors on the old HDD, just on the latest installation. LE:Due note that now the old HDD is used to see if issues re-occur. So please, I am in need of someone who can interpret these windows dump files: Minidump I may have come to some conflicting conclusions. So if someone can clarify each dump/date and the probable cause/error it had; and a final conclusion or solution, we would be very grateful. Also please consult report for other system info I omitted: same link,code: XRWIVLWG If I missed something or if you have any other questions I'll be happy to answer them. Thank you. Good day. Processor: Intel(R) Core(TM)2 Duo CPU T9300 @ 2.50GHz Network Adapter Properties: Broadcom NetLink (TM) Gigabit Ethernet Intel(R) Wireless WiFi Link 4965AGN Video Adapter Properties: Driver Description NVIDIA GeForce 8800M GTX Driver Date 19.08.2009 Driver Version 8.16.11.8681 Driver Provider NVIDIA INF File oem19.inf Hardware ID PCI\VEN_10DE&DEV_060C&SUBSYS_0770152D&REV_A2 Location Information @system32\DRIVERS\pci.sys,#65536;PCI bus %1, device %2, function %3;(1,0,0) PCI Device NVIDIA GeForce 8800M GTX [NoDB] BIOS String Version 62.92.34.0.8 Installed Drivers nvd3dum (8.16.11.8681), nvwgf2um, nvwgf2um Hard Dik Drive: Model ID ST9120823ASG (**older one 120gb**) Model ID WD32000BEKT (new 320gb with fresh OS)

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  • recommendations for efficient offsite remote backup solution of vm's

    - by senorsmile
    I am looking for recommendations for backing up my current 6 vm's(and soon to grow to up to 20). Currently I am running a two node proxmox cluster(which is a debian base using kvm for virtualization with a custom web front end to administer). I have two nearly identical boxes with amd phenom II x4's and asus motherboards. Each has 4 500 GB sata2 hdd's, 1 for the os and other data for the proxmox install, and 3 using mdadm+drbd+lvm to share the 1.5 TB's of storage between the two machines. I mount lvm images to kvm for all of the virtual machines. I currently have the ability to do live transfer from one machine to the other, typically within seconds(it takes about 2 minutes on the largest vm running win2008 with m$ sql server). I am using proxmox's built-in vzdump utility to take snapshots of the vm's and store those on an external harddrive on the network. I then have jungledisk service (using rackspace) to sync the vzdump folder for remote offsite backup. This is all fine and dandy, but it's not very scalable. For one, the backups themselves can take up to a few hours every night. With jungledisk's block level incremental transfers, the sync only transfers a small portion of the data offsite, but that still takes at least a half an hour. The much better solution would of course be something that allows me to instantly take the difference of two time points (say what was written from 6am to 7am), zip it, then send that difference file to the backup server which would instantly transfer to the remote storage on rackspace. I have looked a little into zfs and it's ability to do send/receive. That coupled with a pipe of the data in bzip or something would seem perfect. However, it seems that implementing a nexenta server with zfs would essentially require at least one or two more dedicated storage servers to serve iSCSI block volumes (via zvol's???) to the proxmox servers. I would prefer to keep the setup as minimal as possible (i.e. NOT having separate storage servers) if at all possible. I have also briefly read about zumastor. It looks like it could also do what I want, but it appears to have halted development in 2008. So, zfs, zumastor or other?

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  • Is this iptables NAT exploitable from the external side?

    - by Karma Fusebox
    Could you please have a short look on this simple iptables/NAT-Setup, I believe it has a fairly serious security issue (due to being too simple). On this network there is one internet-connected machine (running Debian Squeeze/2.6.32-5 with iptables 1.4.8) acting as NAT/Gateway for the handful of clients in 192.168/24. The machine has two NICs: eth0: internet-faced eth1: LAN-faced, 192.168.0.1, the default GW for 192.168/24 Routing table is two-NICs-default without manual changes: Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 (externalNet) 0.0.0.0 255.255.252.0 U 0 0 0 eth0 0.0.0.0 (externalGW) 0.0.0.0 UG 0 0 0 eth0 The NAT is then enabled only and merely by these actions, there are no more iptables rules: echo 1 > /proc/sys/net/ipv4/ip_forward /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE # (all iptables policies are ACCEPT) This does the job, but I miss several things here which I believe could be a security issue: there is no restriction about allowed source interfaces or source networks at all there is no firewalling part such as: (set policies to DROP) /sbin/iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT /sbin/iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT And thus, the questions of my sleepless nights are: Is this NAT-service available to anyone in the world who sets this machine as his default gateway? I'd say yes it is, because there is nothing indicating that an incoming external connection (via eth0) should be handled any different than an incoming internal connection (via eth1) as long as the output-interface is eth0 - and routing-wise that holds true for both external und internal clients that want to access the internet. So if I am right, anyone could use this machine as open proxy by having his packets NATted here. So please tell me if that's right or why it is not. As a "hotfix" I have added a "-s 192.168.0.0/24" option to the NAT-starting command. I would like to know if not using this option was indeed a security issue or just irrelevant thanks to some mechanism I am not aware of. As the policies are all ACCEPT, there is currently no restriction on forwarding eth1 to eth0 (internal to external). But what are the effective implications of currently NOT having the restriction that only RELATED and ESTABLISHED states are forwarded from eth0 to eth1 (external to internal)? In other words, should I rather change the policies to DROP and apply the two "firewalling" rules I mentioned above or is the lack of them not affecting security? Thanks for clarification!

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  • FTP server questions

    - by Brad
    I'm currently trying to set up a home FTP server using debian and proftpd and I've run into a problem that has me confused. I have most things set up already, I believe, but I cannot access my ftp server using my external ip. I've forwarded the correct port on my router and I've checked http://www.yougetsignal.com/tools/open-ports/ to be sure that it is, in fact, opened. I've used telnet locally on my server to check that the port accepts connections. I am able to use ftp via LAN. But, I still cannot access anything externally. I'm thinking that there's still some router configuration to be done in order to fix this, such as routing all connections on my ftp port to my server via the internal ip, but I can't find any option on my router to do this. Is this a necessary step? There is an option to use DMZ hosting, but I'd rather avoid it if possible. I can provide additional information as requested, please let me know any information that you think could help at all. Thanks. -Brad PS - I have a Telus Actiontec Modem/Router Update - !! Trying my ftp server out at work, worked! I guess I did set it up correctly after all. What is confusing me, though, is why doesn't the server allow me to connect locally anymore? That seems very weird to me. Also, I don't really understand why I am denied outright if I attempt to connect from the same network using the external address. I'll look into it more when I get home, but thank you guys for your help. Update 2 - I found the problem with not being able to connect locally anymore. I was setting the masquerade address to my external IP and for some reason that was causing it to hang on MLSD when I connected using my LAN address. I've removed the masquerade address and I'm going to check if I need it at work tomorrow. I'll update this page if I find anything.

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  • Remote access to internal machine (ssh port-forwarding)

    - by MacUsers
    I have a server (serv05) at work with a public ip, hosting two KVM guests - vtest1 & vtest2 - in two different private network - 192.168.122.0 & 192.168.100.0 - respectively, this way: [root@serv05 ~]# ip -o addr show | grep -w inet 1: lo inet 127.0.0.1/8 scope host lo 2: eth0 inet xxx.xxx.xx.197/24 brd xxx.xxx.xx.255 scope global eth0 4: virbr1 inet 192.168.100.1/24 brd 192.168.100.255 scope global virbr1 6: virbr0 inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 # [root@serv05 ~]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.100.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr1 xxx.xxx.xx.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0 169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0 0.0.0.0 xxx.xxx.xx.62 0.0.0.0 UG 0 0 0 eth0 I've also setup IP FORWARDing and Masquerading this way: iptables --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE iptables --append FORWARD --in-interface virbr0 -j ACCEPT All works up to this point. If I want to remote access vtest1 (or vtest2) first I ssh to serv05 and then from there ssh to vtest1. Is there a way to setup a port forwarding so that vtest1 can be accessed directly from the outside world? This is what I probably need to setup: external_ip (tcp port 4444) -> DNAT -> 192.168.122.50 (tcp port 22) I know it's easily do'able using a SOHO router but can't figure out how can I do that on a Linux box. Any help form you guys?? Cheers!! Update: 1 Now I've made ssh to listen to both of the ports: [root@serv05 ssh]# netstat -tulpn | grep ssh tcp 0 0 xxx.xxx.xx.197:22 0.0.0.0:* LISTEN 5092/sshd tcp 0 0 xxx.xxx.xx.197:4444 0.0.0.0:* LISTEN 5092/sshd and port 4444 is allowed in the iptables rules: [root@serv05 sysconfig]# grep 4444 iptables -A PREROUTING -i eth0 -p tcp -m tcp --dport 4444 -j DNAT --to-destination 192.168.122.50:22 -A INPUT -p tcp -m state --state NEW -m tcp --dport 4444 -j ACCEPT -A FORWARD -i eth0 -p tcp -m tcp --dport 4444 -j ACCEPT But I'm getting connection refused: maci:~ santa$ telnet serv05 4444 Trying xxx.xxx.xx.197... telnet: connect to address xxx.xxx.xx.197: Connection refused telnet: Unable to connect to remote host Any idea what's I'm still missing? Cheers!!

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  • How do you backup 40+ Centos5.5 servers?

    - by John Little
    We are embarrassed to ask this question. Apologies for our lack of UNIX expertise. We have inherited 40+ centos 5.5 servers, and don't know how to back them up. We need low level clone type images so that we could restore the servers from scratch if we had to replace the HDs etc. We have used the "dd" command, but we assume this only works if you want to back up one local disk to another, not 40 servers to one server with an external USB HD attached. All 40 servers have a pair of mirrored disks (dont know if its HW or SW raid). Most only have 100MB used. SErvers are running apache, zend, tomcat, mysql etc. Ideally we dont want to have to shut them down to backup (but could). We assume that standard unix commands like tar, cpio, rsync, scp etc. are of no use as they only copy files, not partitions, all attributes, groups etc. i.e. do not produce a result which can simply be re-imaged to a new HD to get the serer back from dead. We have a large SAN, a spare windows box and spare unix boxes, but these are only visible to one layer in the network. We have an unused Dell DL2000 monster tape unit, but no sw or documentation for it. WE have a copy of symantec backup exec, but we have no budget for unix client licenses. (The company has negative amounts of money). We need to be able to initiate the backup remotely, as we can only access the servers in person in an emergency (i.e. to restore) Googling returns some applications to do this, e.g. clonezilla - looks difficult to install and invasive. Mondo, only seems to support backup if you are local to the machine. Amanda might be an option, but looks like days/weeks of work to learn and setup? Is there anything built into Centos, or do we have to go the route of installing, learning and configuring a set of backup softwares? Any ideas? This must be a pretty standard problem which goggling doesnt give an obvious answer.

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  • Logitech Optical Mouse Frozen In Middle of Windows XP Pro Screen

    - by Code Sherpa
    Hi. I have a Logitech Optical Mouse/Keyboard. I have been using them just fine with the system drivers for almost a year now. I recently updated my Kaspersky software and rebooted. Now the mouse is frozen in the middle of my screen. I am not able to login to the Windows XP Pro box that has the frozen mouse (because i can't work the mouse) but am able to remote desktop to this computer. Things I know / have tried: When I boot on the problem computer, I am able to use the keyboard, but not the mouse. I have installed the latest version of Logitech's SetPoint (with the updated drivers) on the problem computer (via remote desktop) and that didn't seem to matter. I bought new batteries for the mouse and that didn't matter. I have tried the mouse/keyboard on another computer and the mouse works just fine there. My suspicion is that the Kaspersky install has overwritten a driver of some sort. Things I have not done (and would appreciate detailed steps if you feel this is the way to go): 1) Uninstalled all the mouse drivers on the machine and reboot. Then, reinstall. Note: When I get to the Device Manager I don't see an option for Human Interface Devices (where the mouse device is). Here are my options: Computer, Disk Drives, DVD/CD-Rom drives, Floppy controllers, IDE ATA/ATAPI, Imaging devices, Network Adapters, Other devices, Ports, Processors, Sound, video, and gaming, System devices, USB controllers. Also, I should point out that Video Controller is the only thing under Other devices and it has a yellow exclamation mark. The same is true for all the items under Universal Serial Bus controllers. I think this means I have to update my BIOS but, since my mouse was working just fine without doing that, I don't think that is my problem. So, how do I get to my Mouse Device? 2) Update my BIOS. Note: As pointed out above, I don't think this matters as my mouse was working just fine under my computer's current BIOS version. Thanks for your help.

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