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• Poor NFS Performance: OpenFiler

  - by Safin09

  Good Day Everyone, I have an issue with OpenFiler, a Linux-based operating that converts a computer system into a SAN/NAS appliance. Here is the problem. In my environment we have two Netapp Storevault 500 appliances that I normally perform backups to a NFS share. There are two backup cronjobs that use ghettoVCB to backup two groups of VM's. One group is a pool of 3 VMs. This takes 13 mins to complete. A second job that backups a pool of 5 VMs to a 2nd Storevault appliance which takes 2 hours. We then installed Openfiler on a old server that has 2 core Xeon processors. There is a software RAID 5 process in place. When performing the same backups to a NFS Openfiler share, the first backup job, which takes 13 mins, takes around 4 hours. The second backup job, which takes 2 hours, takes almost 10 hours to complete. This is unacceptable!!!! Especially considering the strain placed on the host ESX Server. I assumed that because of the software RAID 5, the overhead on the CPU explained the long backup times. I then installed Openfiler on a 2nd server, an IBM x306 machine which has a P4 Intel processor. This time no software RAID or any RAID at all. A single 750GB hard drive that contained the OS and the rest of the disk uses to backup VMs to a NFS share. I performed the first backup job of the pool of 3 VMs. This time the backup job took 1 and 1/2 hours to complete instead of 13 mins!!!!!!!!!! Is Openfiler simply poor at being an NFS Server!!!!!!!!!!!!! Has anyone else had these issues with Openfiler?

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• "A disk read error occurred" when booting XP disk image in VirtualBox

  - by intuited

  I'm trying to boot an XP installation cloned into VirtualBox from a real drive. I'm getting the message A disk read error occurred Press Ctrl+Alt+Del to restart whenever* I try to boot the machine. * This is not strictly true: with AMD-V enabled, the boot process appears to not make it this far and instead hangs at a black screen with cursor. I created the VirtualBox image from the original drive using the following method: $ sudo ddrescue -n /dev/sdd sdd.img logfile # completed without errors $ VBoxManage convertfromraw sdd.img disk.vdi The original disk (and the image) contain a single NTFS partition with XP installed on it. The owner of the drive indicates that it did boot okay the last time the system made it that far. The (Pentium 4) system has a broken (enormous) heat sink, so at some point it failed to boot because it would quickly overheat and shut down. If I boot the VM from a live cd, I am able to mount its /dev/sda1 without any problems. I ran ntfsfix and didn't have any luck. I've read through the instructions on doing this. I didn't really follow them. For example, I didn't run MergeIDE before imaging because the machine was not bootable. However, the symptom of that problem seems to be quite different. The emitted message is contained in the volume boot record of the XP partition, which leads me to suspect that this is a problem with the core operating system bootstrap procedure, and not related to anything in the registry. I don't have an XP boot CD.

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• configure apache/webdav readonly for user x, read/write for user y

  - by user82296

  I'm using Apache 2.2 on RHEL 6.x. I can get webdav setup as readonly for user x or readwrite for user x but can't figure out how to make it read only for user x and read/write for user y. I just have a single folder /var/www/html/davtest owned by apache:apache and I want myUser to have readonly access and myAdmin to have read/write access. So far I've only been able to control this by modifying the permissions on the dir /var/www/html/davtest (e.g. if apache has rw then no matter how I set limitExcept below either user can read/write Is this in general possible? <Directory /var/www/html/davtest > DAV on Options Indexes AuthType Digest AuthName myAuth AuthDigestDomain /myD/ http://mysys.x.y/davtest AuthDigestProvider file AuthUserFile /var/www/davDigest/dav_pw require user readOnlyUser <limitExcept get head options> require user myAdmin </limitExcept> </Directory> I've tried various permutations with Limit, LimitExcept and it appears that the only thing that determines who can read/write to the share are the permissions on the files/folders in the share. any guidance, pointers to docs would be greatly appreciated. thanks

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• What are the advantages and disadvantages of the various virtual machine image formats?

  - by Matt

  Xen and Virtualbox etc both support a range of different virtual machine image formats. These are: vmdk, vdi, qcow & qcow2, hdd & vhd. Without any bias toward a particular product, I'm wanting to know what are the advantages and disadvantages of the various formats both from a features perspective, robustness and speed? One piece of info I discovered in a forum post was this: "The major difference is that VDI uses relatively large blocks (1MB) when growing an image, and thus has less overhead for block pointers etc. but isn't ultimately space efficient in the sense that if a single byte is non-zero in such a 1MB block the entire space is used. VMDK in contrast uses 64K blocks, and thus has more management overhead and generally a bit less disk space consumption What offsets this is that VDI is more efficient when it comes to snapshots." You might be thinking, I want to know this because I want to know which format to choose? Not exactly, I'm developing some software which utilises these formats and want to support one or more of them. Simplicity, large disks and ease of development are my main drivers.

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• Limiting bandwidth on internal interface on Linux gateway

  - by Jack Scott

  I am responsible for a Linux-based (it runs Debian) branch office router that takes a single high-speed Internet connection (eth2) and turns it into about 20 internal networks, each with a seperate subnet (192.168.1.0/24 to 192.168.20.0/24) and a seperate VLAN (eth0.101 to eth0.120). I am trying to restrict bandwidth on one of the internal subnets that is consistently chewing up more bandwidth than it should. What is the best way to do this? My first try at this was with wondershaper, which I heard about on SuperUser here. Unfortunately, this is useful for exactly the opposite situation that I have... it's useful on the client side, not on the Internet side. My second attempt was using the script found at http://www.topwebhosts.org/tools/traffic-control.php, which I modified so the active part is: tc qdisc add dev eth0.113 root handle 13: htb default 100 tc class add dev eth0.113 parent 13: classid 13:1 htb rate 3mbps tc class add dev eth0.113 parent 13: classid 13:2 htb rate 3mbps tc filter add dev eth0.113 protocol ip parent 13:0 prio 1 u32 match ip dst 192.168.13.0/24 flowid 13:1 tc filter add dev eth0.113 protocol ip parent 13:0 prio 1 u32 match ip src 192.168.13.0/24 flowid 13:2 What I want this to do is restrict the bandwidth on VLAN 113 (subnet 192.168.13.0/24) to 3mbit up and 3mbit down. Unfortunately, it seems to have no effect at all! I'm very inexperienced with the tc command, so any help getting this working would be appreciated.

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• How To Set Up A Loadbalanced High-Availability Apache Cluster On Windows

  - by bReAd

  Setting up a two-node Apache web server cluster that provides high-availability. In front of the Apache cluster we create a load balancer that splits up incoming requests between the two Apache nodes. Because we do not want the load balancer to become another “Single Point Of Failure”, we must provide high-availability for the load balancer, too. Therefore our load balancer will in fact consist out of two load balancer nodes that monitor each other using heartbeat, and if one load balancer fails, the other takes over silently. The following setup is proposed: Apache node 1: webserver1.example.com (webserver1) – IP address: 192.168.0.101; Apache document root: /var/www Apache node 2: webserver2.example.com (webserver2) – IP address: 192.168.0.102; Apache document root: /var/www Load Balancer node 1: loadb1.example.com (loadb1) – IP address: 192.168.0.103 Load Balancer node 2: loadb2.example.com (loadb2) – IP address: 192.168.0.104 Virtual IP Address: 192.168.0.105 (used for incoming requests) Currently, there are many solutions for Linux machines and there aren't any on windows. I've tried searching a long time for solutions on Windows platform How do I create the virtual IP in windows and perform monitoring and make the load balancer listen to the virtual IP Address?

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• Installing GitHub for Mac - "Github cannot be opened because of a probem"

  - by betitall

  I'm trying to get started using Git for Mac, but I receive an error when I try to run the program. I'm new to GitHub and relatively new to Mac. First, I installed Git using the downloadable .dmg file named "git-1.7.12.3-intel-universal-snow-leopard". I ran the .pkg file contained therein and the install seemed to work fine. I'm using a new macbook pro w/ retina. Then I downloaded the Github for Mac installer, "mac_GitHub for Mac 69.zip". When I double-click the file, it shows that there is a single file of type "Application". Double-clicking that application file produces the error: "GitHub cannot be opened because of a problem". Here are the partial details of that error: Application Specific Information: dyld: launch, loading dependent libraries Dyld Error Message: Library not loaded: @executable_path/../Frameworks/Rebel.framework/Rebel Referenced from: /Applications/GitHub.app/Contents/MacOS/GitHub Reason: no suitable image found. Did find: /Applications/GitHub.app/Contents/MacOS/../Frameworks/Rebel.framework/Rebel: file too short /Applications/GitHub.app/Contents/MacOS/../Frameworks/Rebel.framework/Rebel: file too short Any help would be much appreciated. Thanks.

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• Configuring vsftpd with nginx on Ubuntu 12.04 LTS

  - by arby

  I've attempted to configure a nginx / vsftpd server on Ubuntu 12.04 LTS (via amazon ec2) a couple times now, but I seem to keep making a mistake along the way. Currently, when I try to connect to my ftp server it takes a minute or so before it connects. Then when I issue a command, they all timeout with an operation failed error. Aside from these issues, I'm not completely confident with the file ownership & permissions or the configuration / settings. So, I think it's best if I just re-install and re-configure correctly. I believe the nginx installation comes with a default user of www-data:www-data and web root directory ownership by root:root. Vsftpd, however, needs to have a user created with the same group as the nginx user (www-data), and the same home directory as the nginx server (/usr/share/nginx/www), with g+w chmod permissions granted on that directory. The vsftpd.conf file should disable anonymous logins and enable local logins, file writing, and chroot local users. In my previous config, I had /bin/false set for the ftp user's shell and pam_shells.so disabled. I also had local_umask set to 0027. So, starting with a fresh ec2 instance, I've got: sudo apt-get install vsftpd sudo apt-get install nginx For the firewall I issued the command (not sure if necessary): sudo ufw allow ftp Which commands / config is recommended from here? I only need 1 ftp user that I can use to login with my ftp client to modify the single nginx web domain, which will need php & sql for WordPress.

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• E-mail hosting provider that can set up aliases with wildcards

  - by Richard Downer

  I am looking for an e-mail hosting provider that allow e-mail aliases containing wildcards. In more detail: I own my own domain. I want an e-mail hosting provider to manager e-mail for my domain. Now, to help deal with spam, I often give different e-mail addresses to different organisations. These e-mail addresses always start with the same prefix, but then differ. So, for example, I might give out these e-mail addresses: [email protected] [email protected] [email protected] I want to be able to go to the e-mail provider's control panel and set up an e-mail alias like this: [email protected] -- bounce/discard (because this address has been sold to spammers) joe-*@sample.com -- redirect to [email protected] What's I don't want to do is either have to set up every single e-mail address individually (because I make them up whenever I need them), nor do I want to have a general catch-all for any unrecognised address in my domain (because I don't want to be carpet-bombed with spam when a spammer runs a dictionary attack against my domain name.) Although this seems like a useful feature to have, it seems to be a little-known feature and I've not seen anybody advertise this feature. My current hosting provider offer this but I want to move away from them, so I need another provider that will continue to work with all the e-mail addresses I've been using for years. Alternatively, I could use mail server software that runs on Windows - I have seen some commercial packages offering this feature but they cost more than I can afford - are there any suggestions for low-cost software packages?

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• Can't find standalone Chrome Gmail client that I know exists

  - by Carson

  I'm on Windows. A couple years ago when I switched from Outlook to Gmail (Google Apps), Google provided this awesome little standalone gmail client that was just a single-purpose Chrome install. It launched like a normal application, stayed updated when I updated Chrome. It was Chrome in a separate application that launched only gmail, stayed logged in really well, and "felt" like a gmail mail client, with the gmail interface. It had it's own little red envelope icon, it was a windows app. (I remember there was no Mac equivalent.) I found it while looking through the "this is how you get your company to switch to gmail" documentation that Google provided. I just repaved my box and now I'm looking for this thing again, and I had no idea it would be impossible to find. I've spent literally 2 hours looking, searching, googling, etc. I'm losing my mind. Anyone know how I can get my hands on this? I used it all day every day for 2 years, so I know it exists :), but I can not find it. Any assistance would be gratefully received.

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• Running multiple services on different servers with IPv6 and a FQDN

  - by Mark Henderson

  One of the things NAT has permitted us to do in the past decade is split physical services onto different servers whilst hiding behind a single interface. For example, I have example.com behind a NAT on 192.0.2.10. I port-forward :80 and :443 to my web server. I'm also port forward :25 to my mail server, and :3389 to a terminal server and :8080 to the web interface of my computer that downloads torrents, and the story goes on. So I have 5 port forwardings going to 4 different computers on example.com. Then, I go and get me some neat IPv6. I assign example.com an IPv6 address of 2001:db8:88:200::10. That's great for my websites, but I want to go to example.com:8080 to get to my torrents, or example:3389 to log on to my terminal server. How can I do this with IPv6, as there is no NAT. Sure, I could create a bunch of new DNS entries for each new service, but then I have to update all my clients who are used to just typing example.com to get to either the website or the terminal server. My users are dumber than two bricks so they won't remember to connect to rdp.example.com. What options do I have for keeping NAT-style functionality with IPv6? In case you haven't figured it out, the above scenario is not a real scenario for me, or perhaps anyone yet, but it's bound to happen eventually. You know, with devops and all.

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• Munin 2 data not showing up on graph

  - by letronje

  I have a fresh installation of Munin 2.0.1 on my Ubuntu 12.04 and the first time I tried to view graphs, it showed them properly(After installation, I had to follow http://munin-monitoring.org/wiki/CgiHowto2 to set it up) After that, the graphs show up, but with with just one data point(single vertical line) as if no data is being collected after I tried it for the first time. In Munin 1.4, there was munin-cron which was run every 5 minutes and I saw new data being plotted in the graph atleast every 5 minutes. But If there is no cron job in v2, How does data collection work with Munin2 ? Is the data collected when the graphs are requested ? The file timestamps in /var/lib/munin have not changed after the first time I tried the graphs. But i do see munin-node process running(restarted in several times). I also see no errors in the munin node log files or apache2 log files. Any idea what could be wrong ? Screenshot : http://i.imgur.com/uzuAK.png Also, is there a way to pre-create graphs instead of doing it dynamically, on the fly ?

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• Backing up VMs to a tape drive

  - by Aljoscha Vollmerhaus

  I've got myself one of these fancy tape drives, HP LTO2 with 200/400 GB cartridges. The st driver reports it like this: scsi 1:0:0:0: Sequential-Access HP Ultrium 2-SCSI T65D I can store and retrieve files like a charm using tar, both tar cf /dev/st0 somedirectory and tar xf /dev/st0 work flawless. However, what I really would like to backup are LVM LVs. They contain entire virtual machines with varying partition layouts, so using mount and tar is not an option. I've tried using something like dd if=/dev/VG/LV bs=64k of=/dev/st0 to achieve this, but there seem to be various problems associated with this approach. Firstly, I would like to be able to store more than 1 LV on a single tape. Now I guess I could seek to concatenate the data on the tape, but I think this would not work very well in an automated scenario with many different LVs of various sizes. Secondly, I would like to store a small XML file along with the raw data that contains some information about the VM contained in the LV. I could dump everything to a directory and tar it up - not very desirable, I would have to set aside huge amounts of scratch space. Is there an easier way to achieve this? Thirdly, from googling around it seems like it would be wise to use something like mbuffer when writing to the tape, to prevent what wikipedia calls "shoe-shining" the tape. However, I can't get anything useful done with mbuffer. The mbuffer man page suggests this for writing to a tape device: mbuffer -t -m 10M -p 80 -f -o $TAPE So I've tried this: dd if=/dev/VG/LV | mbuffer -t -m 10M -p 80 -f -d 64k -o /dev/st0 Note the added "-d 64k" to account for the 64k block size of the tape. However, reading data back from a tape written in this way never seems to yield any useful results - dd has been running for ages now, and managed to transfer only 361M of data from the tape. What's wrong here?

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• How to improve Windows Server 2008 R2 to handle many connections?

  - by invisal

  It has been a few days so far that I am trying to figure how to solve this problem. First of all, I am running a website with an average daily page view of 350,000. Previously, all ads management (tracking click and impression that each ads has served) and content were served in a single server with the following spec: Server 1 OS: Windows 2008 R2 64-Bit CPU: Intel® Core™ i5 - 4 cores RAM: 8 GB Storage: 2 x 1 TB hard drives Bandwidth: 10 TB per month To improve our website speed, I decided to separate the ads management script to another dedicated server because we have more than 15 advertisers to 30 advertisers per each page. Server 2 OS: Windows 2008 R2 64-Bit CPU: Intel® Core™ i5 - 4 cores RAM: 4 GB Storage: 2 x 300 GB hard drives Bandwidth: 10 TB per month The Problem The problem is that Server 1 can handle both content and ads system. Now, that I take away the ads system and put it at Server 2. Server 2 can barely serve only ads system. Test First of all, I moved 75% of the ads to Server 2. And then, perform a ping to server: ping -t xxxxx. [I did the ping for 10 minutes and its following similar pattern as below] Reply from xxxxx bytes=32 time=290ms TTL=116 Reply from xxxxx bytes=32 time=289ms TTL=116 Reply from xxxxx bytes=32 time=320ms TTL=116 Reply from xxxxx bytes=32 time=286ms TTL=116 Reply from xxxxx bytes=32 time=286ms TTL=116 Reply from xxxxx bytes=32 time=348ms TTL=116 Reply from xxxxx bytes=32 time=284ms TTL=116 Then, I moved 100% of the ads to Server 2. Then, perform a ping to server again. [I did the ping for 10 minutes and its following similar pattern as below] Reply from xxxxx bytes=32 time=290ms TTL=116 Request timed out Reply from xxxxx bytes=32 time=320ms TTL=116 Reply from xxxxx bytes=32 time=286ms TTL=116 Request timed out Request timed out Reply from xxxxx bytes=32 time=284ms TTL=116 Attempts Increase MaxUserPort and TcpNumConnection Restart the server Increase IIS Max Instances and Instance MaxRequests Server Resource Only 10%-15% of the network connection is used Only 10%-15% of the CPU is used Only 25% of the memory is used

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• Increasing SQL Server / Sage performance with SSD? (Dell PE T410)

  - by Anthony

  I have a client wanting better performance of their Sage (Accpac & CRM) server (v5.5, soon to be v7). It's running on 1 of 2 Hyper-V VMs (Svr2008) on a Dell PE T410 server with 24GB of RAM (1333MHz) & dual quad-core, and both VMs (only their C: drives) are on a single RAID5 array. All clients connect via 1Gb ethernet. The 2nd VM is SBS2008 with 9GB RAM (& all SBS dbs & company data are on a separate RAID5 array), & 3GB RAM for the Svr2008 hypervisor. I've given the Sage/SQL Server VM all the RAM I can (12GB) & SQL Server RAM caching (~8GB, never exceeds ~7.5GB, eg. entire db can now be cached in RAM) and that's helped significantly. Upgrading the Hypervisor to Svr2012 is an obvious step, but probably not a dramatic improvement? What about an SSD for this Sage/SQL Server VM (VM = 100GB, <10GB for the actual live DB) ? Can SSDs be put into the SAS hot-swap bays? Or will I have to use the mobo SATA(3Gbps?) ports, or PCI-E SSD card? Should SSDs be RAIDed for this situation? Or is SSD's higher reliability offsetting the need for RAID1/5/10? (I have nightly full disk backups) New territory for me, would appreciate some feedback. Thanks, Anthony.

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• ASUS P8B WS - Endless Reboots

  - by tuxGurl

  I am running a Intel XEON 1245 with 4GBx2 Kingston Memory ECC Unbuffered DDR3 on an ASUS P8B WS motherboard. BIOS Version 0904 x64. This system is a little over a month old. It is running Ubuntu 11.10. This evening I found the machine turned off. When I tried to restart it, it would POST and stop at the GRUB screen. When I selected Ubuntu and hit enter within 2-3 seconds the would shutdown and restart. If I stayed at the GRUB screen and did nothing the system would not cut out. I tried booting off a USB stick and again 2-3 seconds after selecting 'Try Ubuntu without Installing' the machine will cut power and reboot. Things I have tried so far: Resetting the BIOS using the on board jumper Resetting the BIOS settings to default Disconnecting all external hardware - except keyboard & monitor Booting with 1 stick of RAM - I tried different single sticks Ensured that onboard EPU and GPU boost switches are in the off position. I am running a Memtest86 right now and it has been running for 38+ minutes. This is not an OS problem or an overheating issue (I have a CoolerMaster HAF Case with 3 fans besides the CPU fan) I am at a loss as to what to try next. I think the BIOS is mis-configured somehow but I don't know what to look for.

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• how to split a very large database on sql server

  - by ken jackson

  I have a 90 GB SQL Server database that I want to make more manageable. It stores stock data from 50+ different stocks from 2009 and 2010, and each stock is a separate table. Some tables have hundreds of millions of rows, and other have just a few million. What I want to do is somehow split the database, so that I don't have a single database file that is 90 GB. What I want is to be able to somehow magically split all the tables so that I can backup the 2009 data once and not have to keep on including it in the backup every time I backup the entire database, however, I would like the 2009 data to be included whenever I do a query. Is partitioning the database the way to go? Will it do the above for me, or will I need some other solution? I research partitioning, but I wasn't sure if that would solve all my problems. I wasn't able to find anything that would tell me whether or not it would migrate prexisting data, or whether it only worked for newly inserted data. Any help or pointers would be much appreciated. Thanks in advance, Ken

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• Recommended programming language for linux server management and web ui integration

  - by Brendan Martens

  I am interested in making an in house web ui to ease some of the management tasks I face with administrating many servers; think Canonical's Landscape. This means doing things like, applying package updates simultaneously across servers, perhaps installing a custom .deb (I use ubuntu/debian.) Reviewing server logs, executing custom scripts, viewing status information for all my servers. I hope to be able to reuse existing command line tools instead of rewriting the exact same operations in a different language myself. I really want to develop something that allows me to continue managing on the ssh level but offers the power of a web interface for easily applying the same infrastructure wide changes. They should not be mutually exclusive. What are some recommended programming languages to use for doing this kind of development and tying it into a web ui? Why do you recommend the language(s) you do? I am not an experienced programmer, but view this as an opportunity to scratch some of my own itches as well as become a better programmer. I do not care specifically if one language is harder than another, but am more interested in picking the best tools for the job from the beginning. Feel free to recommend any existing projects that already integrate management of many systems into a single cohesive web ui, except Landscape (not free,) Ebox (ebox control center not free) and webmin (I don't like it, feels clunky and does not integrate well with the "debian way" of maintaining a server, imo. Also, only manages one system.) Thanks for any ideas! Update: I am not looking to reinvent the wheel of systems management, I just want to "glue" many preexisting and excellent tools together where possible and appropriate; this is why I wonder about what languages can interact well with pre-existing command line tools, while making them manageable with a web ui.

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• laptop motherboard "shorts" when connected to adapter

  - by Bash

  Disclaimer: I'm sort of a noob, and this is a long post. Thank you all in advance! summary: completely dead laptop with no signs of life whatsoever (suddenly, for no apparent reason) Here's the deal: Lenovo Y470 (only a few months old with no water or shock damage). It stopped working suddenly (no lights, no sound, even when connecting adapter with or without battery). I tried a different adapter (same electrical rating), but no luck. I disassembled the thing completely, and tried plugging in the adapter and looking for signs of life with all different combinations of components installed (tried all combinations of RAM, CPU, USB power cords, screen, etc plugged in). no luck. Then, I noticed (as I was plugging in the adapter to try for the millionth time) that there was a "spark" for an instant when I first connect the adapter to the power jack. The adapter's LED would then flash (indicating it isn't working or charging). So, I thought the power jack has a short of some sort (due to bad soldering or something). Scanned virtually every single component on the motherboard, and tested the power jack connections with a multimeter. No shorts or damage to anything on the entire motherboard. Now I'm thinking I need to replace the motherboard. But, my actual question: What does this "shorting" when connecting the adapter signify? (btw, the voltage across the power connections and current through it drop to virtually zero when the adapter is connected and "sparks", and they stay that way). The bewildering thing is that there are no damaged components, and the voltage across adapter terminals returns to normal after I disconnect it (so it's not damaged). Please take a look at the pictures (of the motherboard's power connection and nearby components) and see if I'm missing something completely obvious... Links to pictures and laptop and motherboard model: pictures on DropBox Motherboard model: LA-6881P Laptop model: Lenovo IdeaPad Y470

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• Creating mdraid device on top of other existing mdraid devices

  - by Dmitriusan

  I'm considering creating something like "hierarchical raid" and wondering whether it is possible using pure mdraid. Moreover, I'm going to boot from this device. I'm using Ubuntu Server 12.04 LTS with Grub2 bootloader. Motivation behind doing that is: I have 4 x 1tb 7200rpm disks. Two are newer and faster (up to 200mb/sec) and other two are slower (up to 140mb/sec). I want to create RAID-0 device from them. When creating such RAID-0 directly from 4 hard disks, I get summary speed up to ~480mb/sec. That is roughly 4*120mb/sec, so RAID-0 works with speed of the slowest device. I have an idea to create a separate RAID-0 md0 device from 500gb partitions of slower hard disks. Theoretically, this md0 device will have speed 2*140=240~280mb/sec. After that, I'm going to add this md0 device to RAID-0 with faster disks, finishing with up to 3*200=600mb/sec. Stripe-width for this raid will be 2x times bigger than for underlying raid with slow disks. Questions are: is it possible or I'm missing something? will that work as expected? can I boot from such consolidated raid device? any better ideas? any pitfalls? I don't want to use fakeraid for consolidating slow disks for multiple reasons (portability, ability to customize parameters and so on). PS Speed is needed for home virtualization server and just for experience/fun. Reliability is provided via regular automatic backups to a separate device. PPS I considered also using different stripe-width for hard disks with different speed in single raid, but mdraid does not seem to support that.

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• route propogation using OSPF in a network

  - by liv2hak

  I am using Juniper J-series routers to emulate a small telco and VPN customer.The internal routing will be configured with OSPF,MPLS including a default and backup path,RSVP for distributing labels withing the telco,OSPF for distributing routes from the customer edge (CE) routers to the VRF's in the adjacent PE's and finally iBGP for distributing customer routes between VRF's in different PEs. The topology of the network is shown below. The Addressing scheme for the network is as follows. UOW-TAU ******* ge-0/0/0 192.168.3.1 TAU-PE1 ******* ge-0/0/0 10.0.1.0 ge-0/0/1 10.0.2.0 ge-0/0/2 192.168.3.2 TAU-P1 ****** ge-0/0/0 172.16.1.0 ge-0/0/1 172.16.3.1 ge-0/0/2 10.0.2.2 HAM-P1 ****** ge-0/0/0 172.16.3.2 ge-0/0/1 172.16.2.1 ge-0/0/3 10.0.3.2 ACK-P1 ****** ge-0/0/0 172.16.1.2 ge-0/0/2 172.16.2.2 ge-0/0/3 10.0.1.2 HAM-PE1 ******* ge-0/0/0 10.0.3.1 ge-0/0/2 192.168.4.2 UOW-HAM ******* ge-0/0/0 192.168.4.1 I also set up loopback address for each node. I want to setup OSPF so that path to each internal subnet and router loopback address is propogated to all PE and P nodes.I also want to select a single area for PE and P nodes,and on each node I should add each interface that should be propogated. How do I accomplish this.? With my understanding below is the procedure to achieve this.Is the below explanation correct? I set up OSPF on UOW-TAU ge-0/0/0 interface and ge-0/0/1 interface and UOW-HAM ge-0/0/0 interface and ge-0/0/1 interface. let me call this Area 100. Once I have done this I should be able to reach each node from others using ping and traceroute. Any help is highly appreciated.

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• How to connect the virtual networks of vmware guests running on different hosts?

  - by gyrolf

  In a test setup, we are running several virtual machines on a single vmware workstation host. All virtual machines are connected via a "host only" network. This runs fine up to 2 or 3 virtual machines (depending on the host hardware). To allow more virtual machines, we want to use more host machines. Details about the environment and applications: Host PCs are running Windows XP in a corporate intranet. VMware used is Workstation 6.5 Guests are running Windows Server 2003 All guests act as Web Servers One of the guests additionally acts as Windows File server, offering shared folders for the other guests to connect to. Restrictions: VMware guests shall not be visible from the intranet. Changes to the host PC are restricted by corporate policy. In the virtual network, no domain controller exists. All virtual machines are member of the same workgroup. Running the virtual network as NAT is possible. Port forwarding might be used if it does not conflict with ports used by the host PC. Looking for a solution, I found hints about using router or vpn software on the hosts, but without any details how to setup. (I found a similar question Sharing the network between 2 VMware hosts, but the answer was not sufficient for me.)

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• Increasing MSSQL/Sage performance with SSD? (Dell PE T410)

  - by Anthony

  I have a client wanting better performance of their Sage (Accpac & CRM) server (v5.5, soon to be v7). It's running on 1 of 2 Hyper-V VMs (Svr2008) on a Dell PE T410 server with 24GB of RAM (1333MHz) & dual quad-core, and both VMs (only their C: drives) are on a single RAID5 array. All clients connect via 1Gb ethernet. The 2nd VM is SBS2008 with 9GB RAM (& all SBS dbs & company data are on a separate RAID5 array), & 3GB RAM for the Svr2008 hypervisor. I've given the Sage/MSSQL VM all the RAM I can (12GB) & SQL RAM caching (~8GB, never exceeds ~7.5GB, eg. entire db can now be cached in RAM) and that's helped significantly. Upgrading the Hypervisor to Svr2012 is an obvious step, but probably not a dramatic improvement? What about an SSD for this Sage/SQL VM (VM = 100GB, <10GB for the actual live DB) ? Can SSDs be put into the SAS hot-swap bays? Or will I have to use the mobo SATA(3Gbps?) ports, or PCI-E SSD card? Should SSDs be RAIDed for this situation? Or is SSD's higher reliability offsetting the need for RAID1/5/10? (I have nightly full disk backups) New territory for me, would appreciate some feedback. Thanks, Anthony.

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• Red Hat 5.3 on HP Proliant DL380 G5 and failed drive on RAID controller

  - by thinkdreams

  I have a development ERP server here in my office that I assist with support on, and originally the DBA requested a single drive setup for some of the drives on the server. Thus the hardware RAID controller (an HP embedded controller) looks like: c0d0 (2 drive) RAID-1 c0d1 (2 drive) RAID-1 c0d2 (1 drive) No RAID <-- Failed c0d3 (1 drive) No RAID c0d4 (1 drive) No RAID c0d5 (1 drive) No RAID c0d2 has failed. I replaced the drive immediately with a spare using the hot-swap, but the c0d2 continues to mark itself as failed, even when I umount the partition. I'm loathe to reboot the server since I'm concerned about the server coming back up in rescue mode but I'm afraid that's the only way to get the system to re-read the drive. I assumed there was some sort of auto-detection routine for this, but I haven't been able to figure out the proper procedure. I have installed the HP ACU CLI utilties, so I can see the hardware RAID setup. I'd really like to find out what the proper procedure should have been, where I went wrong, and how to correct it now. Obviously this goes without saying I should NOT have listened to the DBA and set the drives up as RAID-1 throughout as was my first instinct. He wasn't worried about data loss, but it sure would have been easier to replace the failed drive. :)

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• Way to speed up load-balanced ssl using nginx?

  - by paulnsorensen

  So the setup for our website is 4 nodes running rails 3 and nginx 1 that all use the same GoDaddy certificate. Because we are a paid site, we have to maintain PCI-DSS compliance and thus have to use the more expensive SSL ciphers -- also we force SSL using Rack. I've recently switched over to Linode's NodeBalancer (which I've read is an HACluster), and we're not getting the performance we'd ideally like. From what I've read, it looks like terminating the SSL on the nodes using the high cipher is what is causing the poor performance, but I'd like to be thorough. Is there anything I can do? I've read about other ways to terminate the SSL before the NodeBalancer (like using stud), but I don't know enough about these solutions. We certainly don't want to do anything experimental or anything that has a single point of failure. If there really isn't anything I can do to speed up the SSL handshake, my alternative would be to support certain pages on Rails using a secure and insecure subdomain. I've found a few guides that walk through that, but my resulting question is in this situation, would it be better to have nginx handle forcing ssl on the secure subdomain instead of rails? Thanks!

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