Search Results

Search found 13164 results on 527 pages for 'missing'.

Page 361/527 | < Previous Page | 357 358 359 360 361 362 363 364 365 366 367 368  | Next Page >

• When modern computers boot, what initial setup of RAM do they execute, and how does it exactly work?

  - by user272840

  I know the title reeks of confusion, and some of you might assume I am just wondering about how the computer boots in general, but I'm not. But I'll sort this out for you people now: 1.Onboard firmware is how mostly all modern computer devices work, whether or not with EFI/UEFI(even without "onboard firmware", older computers still employed bank switching, or similar methods with snap-in firmware, cartridges, etc.) 2.On startup there is no "programs" running in the traditional sense yet, i.e. no kernel, OS, user-applications; all of the instructions, especially the very first instruction, is specified by the Instruction Pointer, I am guessing. How is the IP/PC/etc. set to first point to an address for a BIOS/firmware/etc. instruction, and how do the BIOS instructions map themself out in memory prior to startup? 3.Aside from MMIO, BIOS uses certain RAM addresses to have instructions. The big ? comes in when I ask this ... how does BIOS do this? Conclusion: I am assuming that with the very first instruction there is an initial hardware setup for BIOS prior to complete OS bootup. What I want to know is if it's hardware engineered to always work this way, if there's another step in this bootup method I am missing, a gap of information I am unaware of, or how this all works from the very first instruction, and the RAM data itself.

  Read the article

• unreadable corrupted ntfs partition - lost clusters reported

  - by Eduardo Martinez

  Hi, partition magic is reporting multiple 'bad file record signature' and 'lost clusters' errors on my 250GB samsung sata disk (connected via usb on a xp sp3). Unfortunately PM is unable to fix. PM shows the drive as being NTFS, detects used space ok and also drive name. But PM browser (right click on partition, browse...) won't show anything (as if disk was empty) Windows Explorer is not even picking the drive name and reports 'the file or directory is corrupted and unreadable' PTDD partition table doctor demo tells me the boot sector is fine, and I can see all disk content on its browser - but crucially cannot copy that content over to a new disk (PTDD browser is pretty arid to say the least) Also tried - photorec-6.11.3 - it actually started to extract files but wouldn't keep file names or any folder structure (maybe I missed sth on the configuration options) - find and mount - intellectual scan went well, the only partition on the disk was detected, then tried to mount into p: but got this error on windows explorer: 'p:\ is not accesible. The media is write protected'. Find and mount allows you to create an image from partition but I don't have a disk big enough at hand. Does anyone know if this will keep the extracted files/folders structure intact? I'm starting to think the disk is pretty screwed and my chances to recover this data are slim. Please someone enlighten me with that marvellous piece of software I am missing :-) Thanks in advance

  Read the article

• Squid3 not caching simple request and response

  - by Nick Spacek

  Hi folks, I've pared down my squid.conf to try to figure this out: http_port 80 accel defaultsite=host.to.cache cache_peer ip.to.cache parent 80 0 no-query originserver acl our_sites dstdomain host.to.cache http_access allow our_sites refresh_pattern . 1 20% 4320 Requests are being proxied correctly, so that's a start. Here's a request: GET http://host.to.cache/path?some_param=true Accept: */* Accept-Charset: ISO-8859-1,utf-8 Accept-Encoding: gzip,deflate,sdch Accept-Language: en-US,en Connection: keep-alive Host: host.to.cache User-Agent: myuseragent And the response: Connection: keep-alive Content-Length: 585 Content-Type: application/xml Date: Thu, 06 Jan 2011 18:33:11 GMT Via: 1.0 localhost (squid/3.0.STABLE19) X-Cache: MISS from localhost X-Cache-Lookup: MISS from localhost:80 The response has no caching-related headers, but I thought that refresh_pattern would set a default behavior for responses without caching-related headers. For my test, I wanted to cache everything for one minute at minimum. Am I missing something obvious? I did take a peek at this question: Squid isn't caching ...and ran through the page here: http://www.mnot.net/cache_docs/ briefly, but didn't see anything relevant (not to say that there isn't, I could have missed something). Thanks for any help.

  Read the article

• Trouble getting latest version of Git

  - by TheMethod

  I am using Ubuntu 10.04 LTS. I'm looking at using git as source control for personal projects and Github as a remote repository. I was having trouble pushing a commit to my remote github repo getting the following error message: The requested URL returned error: 403 while accessing https://github.com/Jstall/helloworld.git/info/refs When I did some digging I found that the problem could be me not having the latest version of Git. When I did a --version I found that I have version 1.7.0.4 locally. So I tried to update git using: sudo apt-get install git but get the following error: Reading package lists... Done Building dependency tree Reading state information... Done Package git is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package git has no installation candidate I've tried running: sudo apt-get update and trying again but it didn't seem to make a difference. I'm not sure if it's relevant but I'm also getting a couple of 404's when I run update: Err http://wine.budgetdedicated.com edgy/main Packages 404 Not Found Fetched 4,117B in 0s (5,142B/s) W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/edgy/universe/binary-i386/Packages.gz 404 Not Found [IP: 91.189.91.15 80] W: Failed to fetch http://wine.budgetdedicated.com/apt/dists/edgy/main/binary-i386/Packages.gz 404 Not Found I'm not sure when I should try next. Could anyone suggest a course of action to get this resolved? Any advice would be appreciated. Thanks much!

  Read the article

• Running a service with a user from a different domain not working

  - by EWood

  I've been stuck on this for a while, not sure what permission I'm missing. I've got domain A and domain B, A trusts B, but B does not trust A. I'm trying to run a service in domain A with a user account from domain B and I keep getting Access is Denied. I'm using the FQDN after the username and the password is correct. The user account from domain B is a local administrator on the domain A server, the user account has the logon locally, and as a service permissions. Must. Get. This. Working. Update: I found something interesting in the logs I must have missed. This ought to get me pointed in the right direction. Event ID: 40961 - LsaSrv : The Security System could not establish a secured connection with the server ldap/{server fqdn/fqdn@fqdn} No authentication protocol was available. I've found a few fixes for 40961 but nothing has worked so far. I've verified reverse lookup zones. nslookup resolves the correct dc properly. still workin' at it. Upadte: In response to Evan; I ran " runas /env /user:ftp_user@fqdn "notepad" " then entered the users password and notepad came up. It seems to work successfully. This issue is now resolved. The problem is visible in the screenshot. Windows tries to use the UPN for the user account if you dig your user out of AD with the Browse button. This fails every time even with the right user and password. Simply using the SAM format (Domain\User) works. So simple, yet so annoying. Can't believe I missed this. Thanks to everyone who helped.

  Read the article

• Anti Virus Service does not run - Windows XP SP3 32bit Home

  - by Stefan Fassel

  I have a somewhat strange problem here. I am trying to run Anti Virus Software on my Windows XP Home 32bit System. After a serious crash I had to fall back to an outdated copy of my initial installation and had Windows install 5 years of updates. So far so good. After Intalling a new Anti Virus Software (Bitdefender 2012) everything seemed to be fine, initial scanning went fine and configuration was working. But after restarting the System the Virus Scanner was unable to start up again. Even the Configuration console of the AV Software did not start. I tried scanning the System for malware, but nothing was found. Then I tried a different AV Software (MS Security Essentials), but in the end it did fail to start too. I have tried to start the Service manually, but I seem to be missing the privilege to do so. I am logged in as a Non-"Administrator" User with Admin privileges (Not much choices there on a XP Home System). I cannot switch to Administrator account outside the protected mode. When running Windows in protected mode I am unable to start the AV Software because it does not run in protected mode. I am a bit at loss now...

  Read the article

• Home Sharing and Remote on iTunes causing firewall nags

  - by BoltClock

  It seems that enabling Home Sharing and/or hooking up my iPhone's Remote to iTunes causes Mac OS X Snow Leopard's firewall to freak out and keep nagging every time I launch iTunes to ask if I'd like it to accept incoming connections. If I turn off Home Sharing and forget all Remotes, the nag dialog no longer comes up. I could also disable the firewall, but I think that's a silly thing to do. iTunes is already in the firewall whitelist, so the only thing I know that could cause Mac OS X to nag is a bad application bundle code signature. I checked with this Terminal command: $ codesign -vvv /Applications/iTunes.app/ And sure enough, this is what it outputs: /Applications/iTunes.app/: a sealed resource is missing or invalid /Applications/iTunes.app/Contents/Resources/English.lproj/AutofillSettings.nib/objects.xib: resource added /Applications/iTunes.app/Contents/Resources/English.lproj/iTunesDJSettings.nib/objects.xib: resource added /Applications/iTunes.app/Contents/Resources/English.lproj/MobilePhonePrefs.nib/objects.xib: resource added /Applications/iTunes.app/Contents/Resources/English.lproj/MobilePhoneSetup.nib/objects.xib: resource added /Applications/iTunes.app/Contents/Resources/English.lproj/UniversalAccess.nib/objects.xib: resource added I've tried reinstalling iTunes as suggested by this answer, but Mac OS X still nags about incoming connections and the exact same output is generated when I run the above command again. On my PC, Windows Firewall has never nagged whenever I turn on Home Sharing and hook up Remote on my iPhone. Both computers use iTunes 9.2.1. My Mac runs Mac OS X 10.6.4. Is there anything special I need to do that I might have missed? Or how do I resolve the issue? EDIT: I've updated to iTunes 10, but the nags on my Mac are still there and only go away if I turn off Home Sharing and Remote. EDIT 2: I've updated to Remote 2.0 on my iPhone, but the firewall nags are persisting. Has anyone else had this firewall issue at all?

  Read the article

• SQL Error (1064) when importing data from SQL file

  - by mejpark

  I have a MySQL database, which was originally set up with the default latin1 character set and latin1_swedish_ci collation. I was using the database like this for sometime, until I noticed strange characters on my production web site, which is powered by a database exported from my development machine. At this point, I changed the default character set of the database and tables to utf8 and the collation to utf8_unicode_ci, converted the latin1 data inside each table to utf8 (using the 'convert data' option) and exported the database as a single SQL file using HeidiSQL. When the resulting SQL file is opened in Notepad++, several characters are rendered incorrectly. For example, en dashes (-) are displayed as – and e with accent (é) are displayed as é. I changed the encoding of the file from ANSI to UTF-8 (using the encoding menu option in Notepad++) and the offending characters are rendered correctly. I saved the new utf8-encoded SQL file and attempted to import the contents into the MySQL database on my production server. The import process fails with following error: /* SQL Error (1064): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?# -------------------------------------------------------- # Host: ' at line 1 */ /* Error with snippets directory: The specified path was not found */ The head of the SQL file: # -------------------------------------------------------- # Host: 127.0.0.1 # Server version: 5.1.33-community # Server OS: Win32 # HeidiSQL version: 6.0.0.3773 # Date/time: 2011-04-20 09:48:36 # -------------------------------------------------------- It chokes on the first line of the file, which is commented out. Why is this happening? I didn't have a problem loading data from SQL files until I changed the character set and collation of the database. I came up with an ugly workaround to this problem by performing following steps: Export database as single SQL file using HeidiSQL Open resulting file in Notepad++ and convert from ANSI to UTF-8 encoding Create new empty file in Notepad++, paste in UTF-8 and save file normally What am I missing here?

  Read the article

• VLAN Through Switch Doesn't Work

  - by vcsjones

  I have the following scenario: I have a Cisco Aironet 1040 access point. I have it configured with two SSIDs, each going to a different VLAN. So: SSID internal : VLAN 90 SSID guest : VLAN 70 On the router side, I have a Cisco RV220W (with the radios now turned off) and have setup VLANs with like VLAN IDs. VLAN 90 : 192.168.90.0/24 VLAN 70 : 192.168.70.0/24 As far as DHCP is concerned, each VLAN has a "DHCP Server" in the router's configuration: So with the access point connected directly to the router, everything works great. I connect to the internal network, and I get a 192.168.90.x address, and the guest network gets a 70.xxx address. Next I introduced a Cisco SG200-50 PoE switch between the router and the access point. The port is configured as a trunk port, so the VLAN tags should go right through the switch back to the router. However, when something is connected to the access point, nothing works. It isn't able to get an IP address, and manually assigning one doesn't seem to let any traffic route. Given that the access point works correctly when connected to the router directly, I believe the switch is misconfigured. What am I missing here? What can I use to better diagnose what the problem might be? It's small business equipment, so CLI access is not available. Below are screenshots of the switch's config. The access point is connected to GE2.

  Read the article

• Blink build with Xcode failed

  - by Merci

  I found a GPL-ed SIP client for Mac, Blink. I'd like to build it from source since the binaries are only available as paid download. Just FYI i'm studying programming at university but have no experience in building complex application from source. After downloading the content of the repository i opened the Xcode project and tried to build on OS X 10.7, Xcode 4.2.1. Unfortunately the build fail with 1 error and many warnings Most of the warnings are like this: Attribute Unavailable: Custom Identifiers in Interface Builder versions prior to 3.2 The error message is: Apple Mach-O Linker (ld) Error Command /Developer/usr/bin/clang failed with exit code 1 preceded by the warning Apple Mach-O Linker (ld) Warning directory not found for option '-L/Users/Sergio/Downloads/Blink/devel.ag-projects.com/repositories/public/blink-cocoa/Distribution/Frameworks' I notice that in the list of required files i have this files missing: Dependencies/Frameworks libgcrypt.11.6.0.dylib libgcrypt.11.dylib libgnutls-extra.26.dylib libgnutls.26.dylib libgpg-error.0.dylib libintl.8.dylib liblzo.1.dylib libtasn1.3.dylib Dependencies/Resources lib Frameworks/Linked Frameworks Sparkle.framework Products Blink.app It should be possible to download these files somewhere. Unfortunately googling did not help. There's no documentation on the project site.

  Read the article

• Prevent nginx from redirecting traffic from https to http when used as a reverse proxy

  - by Chris Pratt

  Here's my abbreviated nginx vhost conf: upstream gunicorn { server 127.0.0.1:8080 fail_timeout=0; } server { listen 80; listen 443 ssl; server_name domain.com ~^.+\.domain\.com$; location / { try_files $uri @proxy; } location @proxy { proxy_pass_header Server; proxy_redirect off; proxy_set_header Host $http_host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Forwarded-Proto https; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Scheme $scheme; proxy_connect_timeout 10; proxy_read_timeout 120; proxy_pass http://gunicorn; } } The same server needs to serve both HTTP and HTTPS, however, when the upstream issues a redirect (for instance, after a form is processed), all HTTPS requests are redirected to HTTP. The only thing I have found that will correct this issue is changing proxy_redirect to the following: proxy_redirect http:// https://; That works wonderfully for requests coming from HTTPS, but if a redirect is issued over HTTP it also redirects that to HTTPS, which is a problem. Out of desperation, I tried: if ($scheme = 'https') { proxy_redirect http:// https://; } But nginx complains that proxy_redirect isn't allowed here. The only other option I can think of is to define the two servers separately and set proxy_redirect only on the SSL one, but then I would have duplicate the rest of the conf (there's a lot in the server directive that I omitted for simplicity sake). I know I could also use an include directive to factor out the redundancy, but I really want to keep just one conf file without any dependencies. So, first, is there something I'm missing that will negate the problem entirely? Or, second, if not, is there any other way (besides including an external file) to factor out the redundant config information so that I can separate out the HTTP and HTTPS versions of the server config?

  Read the article

• Windows : Map-a-network-drive to a remote Shared-Folder (on QNAP NAS) using OpenVPN

  - by spelltox

  Provided my lack of networking knowledge, I've been struggling with this issue for quite a few days now : I have a QNAP-TS212 NAS on which i've created a shared-folder (mostly excel files). All the computers in the local network (windows) are able to access it without any problem. Now, i want to access that shared-folder remotely (windows client), so : I enabled OpenVPN (and PPTP) in QNAP admin. Installed OpenVPN on the remote client. Applied the configuration file that the QNAP generated - Configuration (openvpn.ovpn) : client dev tun script-security 3 proto udp remote ***MY_WAN_IP*** 1194 resolv-retry infinite nobind ca ca.crt auth-user-pass reneg-sec 0 cipher AES-128-CBC comp-lzo OpenVPN connect successfully from the remote client. Now, here's my problem : I can ping the NAS (got IP 10.8.0.1) from the remote client, But when i try to map-a-network-drive, i don't see the shared folder or the NAS or any of the other computers in the network... I checked - all computers are in "WORKGROUP" workgroup. I'm probably missing some basic knowledge, So - any help would be greatly appreciated ! Many thanks.

  Read the article

• Amazon AWS VPN how to open a port?

  - by Victor Piousbox

  I have a VPN with public and private subnets; I am considering only public subnet for now. The node 10.0.0.23, I can ssh into it. Let's say I want to connect to MySQL on the node using its private address: ubuntu@ip-10-0-0-23:/$ mysql -u root -h 10.0.0.23 ERROR 2003 (HY000): Can't connect to MySQL server on '10.0.0.23' (111) ubuntu@ip-10-0-0-23:/$ mysql -u root -h localhost Welcome to the MySQL monitor. Commands end with ; or \g. --- 8< --- snip --- 8< --- mysql> The port 3306 is not reachable if I use the private IP? My security group allows port 3306 inbound from 0.0.0.0/0 AND from 10.0.0.0/24. Outbound, allowed all. The generic setup done by Amazon through their wizard does not work... I add ACL that allows everything for everybody, still does not work. What am I missing?

  Read the article

• Why cache static files with Varnish, why not pass

  - by Saif Bechan

  I have a system runnning nginx / php-fpm / varnish / wordpress and amazon s3. Now I have looked at a lot of configuration files while setting up the system, and in all of them I found something like this: /* If the request is for pictures, javascript, css, etc */ if (req.url ~ "\.(jpg|jpeg|png|gif|css|js)$") { /* Remove the cookie and make the request static */ unset req.http.cookie; return (lookup); } I do not understand why this is done. Most of the examples also run NginX as a webserver. Now the question is, why would you use the varnish cache to cache these static files. It makes much more sense to me to only cache the dynamic files so that php-fpm / mysql don't get hit that much. Am I correct or am I missing something here? UPDATE I want to add some info to the question based on the answer given. If you have a dynamic website, where the content actually changes a lot, chaching does not make sense. But if you use WordPress for a static website for example, this can be cached for long periods of time. That said, more important to me is static conent. I have found a link with some test and benchmarks on different cache apps and webserver apps. http://nbonvin.wordpress.com/2011/03/14/apache-vs-nginx-vs-varnish-vs-gwan/ NginX is actually faster in getting your static content, so it makes more sense to just let it pass. NginX works great with static files. -- Apart from that, most of the time static content is not even in the webserver itself. Most of the time this content is stores on a CDN somewhere, maybe AWS S3, something like that. I think the varnish cache is the last place where you want to have you static content stored.

  Read the article

• Why java -version returning a different version than the one defined in JAVA_HOME?

  - by Shekhar

  I am trying to set JAVA_HOME in Ubuntu OS. I have copied jdk 1.7 in /usr/lib/jvm and set JAVA_HOME in /etc/profile file. Contents of /usr/lib/jvm folder are as follows : shekhar@ubuntu:~$ ls /usr/lib/jvm/ default-java java-1.6.0-openjdk java-6-openjdk java-6-openjdk-i386 jdk1.7.0_01 java-1.5.0-gcj-4.6 java-1.6.0-openjdk-i386 java-6-openjdk-common java-7-openjdk-i386 and last few lines of /etc/profile file are as follows : export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_01 export PATH=$PATH:$JAVA_HOME/bin After finishing all this when I run java -version command I get following output : shekhar@ubuntu:~$ java -version java version "1.6.0_24" OpenJDK Runtime Environment (IcedTea6 1.11.4) (6b24-1.11.4-1ubuntu0.12.04.1) OpenJDK Server VM (build 20.0-b12, mixed mode) and when I run ls -lah command I get following output : shekhar@ubuntu:~$ ls -lah /usr/bin/java lrwxrwxrwx 1 root root 22 Sep 29 09:58 /usr/bin/java -> /etc/alternatives/java shekhar@ubuntu:~$ ls -lah /etc/alternatives/java lrwxrwxrwx 1 root root 45 Sep 29 09:58 /etc/alternatives/java -> /usr/lib/jvm/java-6-openjdk-i386/jre/bin/java Can anyone please tell me which thing I am missing? Why Ubuntu is still pointing to open jdk and not to my jdk 7? PS : I have seen this similar question and its answers but that question is related to Windows OS and not for Ubuntu so I am reposting this similar question for Ubuntu.

  Read the article

• Clarification for setting up SSH terminal access on Cisco IOS

  - by Matt Malesky

  I'm attempting to set up SSH on a Cisco 2811 and having some difficulties. The first step to this should be running crypto key generate rsa I seem to be missing this though: better#crypto key generate rsa ^ % Invalid input detected at '^' marker. better# Furthermore, the only available commands I have in the crypto key namespace are lock and unlock, which seem to indicate a locked keypair (for which I don't know the password): better#crypto key ? lock Lock a keypair. unlock Unlock a keypair. better#crypto key unlock ? rsa RSA keys better#crypto key unlock rsa %% Please enter the passphrase: %% Unlocking failed. . better# More or less, I'm asking what exactly this might mean, and if I actually do have certificates already here (used router)? Otherwise, how can I solve this? It's my first time configuring this feature, but I definitely believe it's part of my IOS. Speaking of my IOS, I'm running the image c2800nm-advsecurityk9-mz.124-24.T6.bin I'll also note that I have my hostname and ip domain-name configured. I'll also give you a dir flash: below if it's at all of use: better#dir flash: Directory of flash:/ 2 -rw- 2748 Jul 27 2009 14:03:52 +00:00 sdmconfig-2811.cfg 3 -rw- 931840 Jul 27 2009 14:04:10 +00:00 es.tar 4 -rw- 1505280 Jul 27 2009 14:04:32 +00:00 common.tar 5 -rw- 1038 Jul 27 2009 14:04:46 +00:00 home.shtml 6 -rw- 112640 Jul 27 2009 14:05:00 +00:00 home.tar 7 -rw- 1697952 Jul 27 2009 14:05:26 +00:00 securedesktop-ios-3.1.1.45-k9.pkg 8 -rw- 415956 Jul 27 2009 14:05:46 +00:00 sslclient-win-1.1.4.176.pkg 9 -rw- 38732900 Dec 8 2011 06:28:56 +00:00 c2800nm-advsecurityk9-mz.124-24.T6.bin 64016384 bytes total (20598784 bytes free) better#

  Read the article

• Windows 7 can't see wireless printer

  - by Chance Robertson

  I have a P1102W printer from HP. I have a Windows 7 machine. I have a MacBook Pro. I setup the printer following the instructions from the Windows 7 machine. I am able to print from the Mac but not the Windows 7 machine. And to add, I am not able to print from any Windows 7 machines. The MacBook Pro address is 198.168.2.115, the Windows machine is 192.168.2.117, and the printer in 192.168.2.140. I can ping the printer from the Mac. I can ping the Windows 7 machine from the mac. I can ping the mac from the windows 7 machine. When I try to ping the printer from the Windows 7 machine I get destination unreachable. I can browse to the printer IP address from the mac and not the Windows 7. I have turned off the firewall on the Windows 7 machine and turned on network sharing. Is there something else I am missing. I can connect the printer with a USB cable to the Windows machine and print. I can not get the Windows machine to see the printer even though they are on the same network.

  Read the article

• Network latency and speed of light

  - by James

  This was kinda of covered by the following Is minimum latency fixed by the speed of light? , but i would like to add the follow up a bit. The scenario is as follows; we have two opposing sites one on the West Coast of the US and one in Ireland. The customer is in central Europe, and has requested a latency test. Ireland gives responses of ~65-70ms. However the West Coast guys claim to be faster with a response of 60ms. Now a quick check says that light in fiber would take about 42ms to make the trip to the States and 8.5ms to Ireland. So obviously this is a single hop and does not include routers, switches, firewalls, protocol overhead etc. Would I be right to call BS on their figures? As a final note I tested a ping to Google IP address that was allegedly on the west coast from a site that covered a similar distance and was amazed to get a response time of 20ms. Suggesting ICMP packets that travel twice the speed of light. So A) what am I missing B) Am I right to suspect shenanigans? UPDATE: Guys thanks so far for your help and I have been reading various previous questions on this. About 5 years I had an issue where the hop from the UK to Ireland added 10ms of latency no matter what we did. In the end I moved the servers; So imagine my surprise when I have guys that claim they are 5ms faster with a transatlantic trip. So again should I call BS? Oh and assume both sites are normal mortals that don't have access to Google magical routing, warp dives or flux capacitors. :)

  Read the article

• Can enabling a RAID controller's writeback cache harm overall performance?

  - by Nathan O'Sullivan

  I have an 8 drive RAID 10 setup connected to an Adaptec 5805Z, running Centos 5.5 and deadline scheduler. A basic dd read test shows 400mb/sec, and a basic dd write test shows about the same. When I run the two simultaneously, I see the read speed drop to ~5mb/sec while the write speed stays at more or less the same 400mb/sec. The output of iostat -x as you would expect, shows that very few read transactions are being executed while the disk is bombarded with writes. If i turn the controller's writeback cache off, I dont see a 50:50 split but I do see a marked improvement, somewhere around 100mb/s reads and 300mb/s writes. I've also found if I lower the nr_requests setting on the drive's queue (somewhere around 8 seems optimal) I can end up with 150mb/sec reads and 150mb/sec writes; ie. a reduction in total throughput but certainly more suitable for my workload. Is this a real phenomenon? Or is my synthetic test too simplistic? The reason this could happen seems clear enough, when the scheduler switches from reads to writes, it can run heaps of write requests because they all just land in the controllers cache but must be carried out at some point. I would guess the actual disk writes are occuring when the scheduler starts trying to perform reads again, resulting in very few read requests being executed. This seems a reasonable explanation, but it also seems like a massive drawback to using writeback cache on an system with non-trivial write loads. I've been searching for discussions around this all afternoon and found nothing. What am I missing?

  Read the article

• How to Enable IPtables TRACE Target on Debian Squeeze (6)

  - by bernie

  I am trying to use the TRACE target of IPtables but I can't seem to get any trace information logged. I want to use what is described here: Debugger for Iptables. From the iptables man for TRACE: This target marks packes so that the kernel will log every rule which match the packets as those traverse the tables, chains, rules. (The ipt_LOG or ip6t_LOG module is required for the logging.) The packets are logged with the string prefix: "TRACE: tablename:chain- name:type:rulenum " where type can be "rule" for plain rule, "return" for implicit rule at the end of a user defined chain and "policy" for the policy of the built in chains. It can only be used in the raw table. I use the following rule: iptables -A PREROUTING -t raw -p tcp -j TRACE but nothing is appended either in /var/log/syslog or /var/log/kern.log! Is there another step missing? Am I looking in the wrong place? edit Even though I can't find log entries, the TRACE target seems to be set up correctly since the packet counters get incremented: # iptables -L -v -t raw Chain PREROUTING (policy ACCEPT 193 packets, 63701 bytes) pkts bytes target prot opt in out source destination 193 63701 TRACE tcp -- any any anywhere anywhere Chain OUTPUT (policy ACCEPT 178 packets, 65277 bytes) pkts bytes target prot opt in out source destination edit 2 The rule iptables -A PREROUTING -t raw -p tcp -j LOG does print packet information to /var/log/syslog... Why doesn't TRACE work?

  Read the article

• Raid-z unaccessible after putting one disk offline

  - by varesa

  I have installed FreeNAS on a test server, with 3x 1Tb drives. They are setup in raidz. I tried to offline one of the disks (from the FreeNAS web-ui), and the array became degraded, as I think it should. The problem is with the array becoming unaccessible after that. I thought a raid like that should be able to run fine with one of the disks missing. Atleast very soon after I offline'd and pulled out the disk, the iSCSI share disappeared from a ESXi host's datastores. I also ssh'd into the FreeNAS server, and tried just executing ls /mnt/raid (/mnt/raid/ being the mount point). The whole terminal froze, not accepting ^C or anything. # zpool status -v pool: raid state: DEGRADED status: One or more devices are faulted in response to IO failures. action: Make sure the affected devices are connected, then run 'zpool clear'. see: http://www.sun.com/msg/ZFS-8000-HC scrub: none requested config: NAME STATE READ WRITE CKSUM raid DEGRADED 1 30 0 raidz1 DEGRADED 4 56 0 gptid/c8c9e44c-08e1-11e2-9ba6-001b212a83ea ONLINE 3 60 0 gptid/c96f32d5-08e1-11e2-9ba6-001b212a83ea ONLINE 3 63 0 gptid/ca208205-08e1-11e2-9ba6-001b212a83ea OFFLINE 0 0 0 errors: Permanent errors have been detected in the following files: /mnt/raid/ raid/iscsivol:<0x0> raid/iscsivol:<0x1> Have I understood the workings of a raidz wrong, or is there something else going on? It would not be nice to have the same thing happen on a production system...

  Read the article

• How does USB device recognition work?

  - by GorillaSandwich

  I'm curious how USB device recognition works in Windows. I imagine it's something like this: When you plug in a device, it tells Windows "here's my device ID to tell you what I am" Windows looks to see if any drivers have been installed that match that device ID. The driver probably tells Windows what the device should be called - like "BlackBerry Curve" or "Canon Printer" If so, it somehow associates that device with that driver Otherwise, it looks for a matching driver online (if you let it) Am I right? If so, that still leaves some questions. When you install drivers, where do they go? Are they files in a folder, or do they get added to the registry? What is Windows doing when it first recognizes the device, thinks, and finally says "your new device is installed and ready to use?" Where does Windows look for missing drivers? Is it in their own database? Do device manufacturers submit drivers to Microsoft for inclusion there? Can anybody explain how this process really works? Also, do other OSes do this differently?

  Read the article

• AD domain on web servers behind NAT - DNS issues?

  - by Ant

  I'm trying to setup an AD domain to manage the security between two Windows Server 2008 webservers that will sooner or later use NLB to balance website requests. I've hit a problem which I think is a simple solution and is down to DNS. My website domain is mydomain.com. The two servers are running behind a NAT firewall on the 10.0.0.0 IP range. I've setup the AD domain to be called ad.mydomain.com (as recommended by MS and a few other answers to questions on here). The second web server however doesn't want to join the domain, and gives an error pinning the problem on DNS - "ensure that the domain name is typed correctly" even though it queries the SRV record successfully and gets the correct DC back - dc.ad.mydomain.com. Doing a dcdiag /test:dns on the DC gives the Delegation error 'DNS Server dc.mydomain.com Missing glue A record'. I have a feeling I need to add something to the public DNS so that it in some way knows about ad.mydomain.com. Can anyone suggest whether I'm on the right track in adding something to the public DNS? Or whether it's something else? Many thanks

  Read the article

• Problems installing GIT on Ubuntu through SSH

  - by jamadri

  I'm having trouble installing git using this command: sudo apt-get install git-core It's giving me the problems below and I'm not quite sure how to get this to work correctly. I try running sudo apt-get update and after it just gives me problems. If anyone knows how to solve this or a possible way of getting GIT on your machine differently it would be of much help. I've never had a problem with using apt-get. Do you want to continue [Y/n]? y WARNING: The following packages cannot be authenticated! liberror-perl git-core patch Install these packages without verification [y/N]? y Err http://us.archive.ubuntu.com jaunty/main git-core 1:1.6.0.4-1ubuntu2 404 Not Found [IP: 91.189.92.183 80] Err http://us.archive.ubuntu.com jaunty/main patch 2.5.9-5 404 Not Found [IP: 91.189.92.183 80] Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/g/git-core/git-core_1.6.0.4- 1ubuntu2_amd64.deb 404 Not Found [IP: 91.189.92.183 80] Failed to fetch http://us.archive.ubuntu.com/ubuntu/pool/main/p/patch/patch_2.5.9- 5_amd64.deb 404 Not Found [IP: 91.189.92.183 80] E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing? Anything reply that can help fix this would be helpful. I'm not sure if it's the git servers or my connection that might be the problem. I've used apt-get to pull other things, it's just failing with git.

  Read the article

• LVM2 volume group lost

  - by MrG

  I updated one of my servers, but - although I took care not to modify - the volume groups on /dev/sdb1 were lost, although the physical volumes seem to be still there: [root@server ~]# pvscan PV /dev/sda2 VG VolGroup lvm2 [465,16 GiB / 0 free] PV /dev/sdb1 lvm2 [1,82 TiB] Total: 2 [2,27 TiB] / in use: 1 [465,16 GiB] / in no VG: 1 [1,82 TiB] [root@server ~]# pvs -v Scanning for physical volume names PV VG Fmt Attr PSize PFree DevSize PV UUID /dev/sda2 VolGroup lvm2 a-- 465,16g 0 465,16g HftbaD-MBs0-3p7D-6O13-CrzU-T9Gb-6W0ofB /dev/sdb1 lvm2 a-- 1,82t 1,82t 1,82t dD4XZP-WStA-61xV-5Sff-ifmW-R4rR-JenHoU [root@server ~]# pvck -d -v /dev/sdb1 Scanning /dev/sdb1 Found label on /dev/sdb1, sector 1, type=LVM2 001 Found text metadata area: offset=4096, size=1044480 Found LVM2 metadata record at offset=10752, size=1037824, offset2=0 size2=0 Found LVM2 metadata record at offset=9216, size=1536, offset2=0 size2=0 Found LVM2 metadata record at offset=7168, size=2048, offset2=0 size2=0 Found LVM2 metadata record at offset=5632, size=1536, offset2=0 size2=0 I attempted to fix it as described here and was able to extract the 4 meta data sets listed above (using i.e. dd bs=1 skip=5632 count=1536 if=/dev/sdb1 of=output.file), none of them includes the lv_data which I'm missing. Please advise how I could access the files which should be on /dev/sdb1 there. Any help is appreciated!

  Read the article

< Previous Page | 357 358 359 360 361 362 363 364 365 366 367 368  | Next Page >