- Published:
- March 23, 2009 – 9:14 am
- Author:
- By Dave
Recently I started seeing this error while provisioning Xen VPSes on a server with 8GB of RAM: 12[2009-03-23 15:51:40 xend.XendDomainInfo 3310] DEBUG (XendDomainInfo:1603) XendDomainInfo.destroy: domid=None [2009-03-23 15:51:40 xend 3310] ERROR (xmlrpclib2:184) (12, ‘Cannot allocate memory’) I checked the memory, and sure enough, all of the VPSes were using up the memory. More specifically, dom0 (the main server) had ‘ballooned’ and begun to take up 3GB of RAM, this is more than the system should need: 12[2009-03-22 18:03:08 xend.XendDomainInfo 3310] DEBUG (XendDomainInfo:1113) Setting memory target of domain Domain-0 (0) to 2903 MiB. [2009-03-22 18:03:09 xend 3310] DEBUG (balloon:127) Balloon: 537840 KiB free; need 537600; done. Basically when memory ballooning is set, the memory available to the main hypervisor will have a minimum value set and will balloon according to the current requirements. This setting is in the config file which for me is at /etc/xen/xend-config.sxp: 1234# Dom0 will balloon out when….
Categories: CentOS,Configurations,System Administration,Xen
Tagged: CentOS, dom0, memory, Xen
- Published:
- March 17, 2009 – 3:58 pm
- Author:
- By Dave
Running sudo apt-get upgrade, I started getting this error: 1Reading package lists… Done 1W: GPG error: http://ppa.launchpad.net intrepid Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 313D312748A22A95 1W: You may want to run apt-get update to correct these problems Ah ha! But apt-get update is the command causing this problem. The solution is to import this key from the gpg servers; I don’t know why this isn’t done automatically, but here is it: 1sudo apt-key adv –recv-keys –keyserver keyserver.ubuntu.com 313D312748A22A95; gpg –export –armor 313D312748A22A95 | sudo apt-key add – Resulting in: 123456Executing: gpg –ignore-time-conflict –no-options –no-default-keyring –secret-keyring /etc/apt/secring.gpg –trustdb-name /etc/apt/trustdb.gpg –keyring /etc/apt/trusted.gpg –recv-keys –keyserver keyserver.ubuntu.com 313D312748A22A95 gpg: requesting key 48A22A95 from hkp server keyserver.ubuntu.com gpg: key 48A22A95: public key "Launchpad PPA for Filip Brcic" imported gpg: Total number processed: 1 gpg: unchanged: 1 OK Congrats! sudo apt-get….
Categories: Configurations,Shell,System Administration,Ubuntu
Tagged: apt-get, gpg, Ubuntu
- Published:
- January 8, 2009 – 10:28 am
- Author:
- By Dave
The Remote Desktop connection settings for Windows Server 2008, and I believe Windows Vista, includes 3 levels of service: Don’t allow connections to this computer Allow connections from computers running any version of Remote Desktop (less secure) Allow connections only from computers running Remote Desktop with Network Level Authentication (more secure) At first blush, you would probably choose the “more secure” option. Practically, this mainly means that it only allows connections from the latest Remote Desktop software in Windows Vista. It is probably another attempt by Microsoft to force consumers and businesses into upgrading to Windows Vista. But… I digress. When connecting with an older Terminal Services (TS) client in XP or even Vista, you will get this message: “Remote computer requires Network Level Authentication, which your computer doesn’t support” Not all is lost. There are two ways around this. The first and most obvious solution is to select the….
Categories: Configurations,Security,System Administration,Windows
Tagged: credssp, network level authentication, nla, remote desktop, Security
- Published:
- December 29, 2008 – 3:58 pm
- Author:
- By Dave
I recently got stuck while trying to install Headless Virtualbox on a Centos 5.2 server per the directions at Howtoforge here. The RPM failed with the error that it couldn’t find the kernel source. I thought I had already installed kernel-devel, and confirmed that I did. The instructions were to define the KERN_DIR variable like so: $ export KERN_DIR=/usr/src/kernels/2.6.18-92.1.22.el5-i686/ $ /etc/init.d/vboxdrv setup Stopping VirtualBox kernel module [ OK ] Removing old VirtualBox netflt kernel module [ OK ] Removing old VirtualBox kernel module [ OK ] Recompiling VirtualBox kernel module [ OK ] Starting VirtualBox kernel module [FAILED] (modprobe vboxdrv failed. Please use ‘dmesg’ to find out why) dmesg shows this: vboxdrv: disagrees about version of symbol struct_module Interesting! After several missteps, it turns out there is a separate development rpm for the PAE kernel: $ yum install kernel-PAE-devel After that installs, we are good: $ export KERN_DIR=/usr/src/kernels/2.6.18-92.1.22.el5-PAE-i686/ $ /etc/init.d/vboxdrv….
Categories: Configurations,Linux,Programs,Shell,Software,System Administration
Tagged: error, kernel, virtualbox
- Published:
- December 7, 2008 – 2:10 am
- Author:
- By Dave
Readers should note that this applies to Ubuntu 8.10 Intrepid Ibex only! ZFS is a relatively new filesystem created by Sun. It is released under the CDDL License which is incompatible with Linux’s GPL License, meaning that it can not be installed natively in the kernel. Therefore, for not it is relegated to addon packages and is brought to Ubuntu via the Fuse framework. For more information on this see the Ubuntu Wiki article on ZFS. The wiki article also explains this, but getting ZFS installed on Ubuntu is actually pretty straightforward by issuing these commands: $ sudo echo “deb http://ppa.launchpad.net/brcha/ubuntu intrepid main” >> /etc/apt/sources.list.d/zfs-fuse.list $ sudo echo “deb-src http://ppa.launchpad.net/brcha/ubuntu intrepid main” >> /etc/apt/sources.list.d/zfs-fuse.list $ sudo apt-get update $ sudo apt-get install zfs-fuse This installs zfs onto your system. Now to create your raid-z array! Its dead simple. $ sudo zpool create media -m /storage raidz /dev/sda /dev/sdb /dev/sdc In….
Categories: Configurations,Linux,Shell,System Administration,Ubuntu
Tagged: filesystem, RAID, sysadmin, zfs
- Published:
- November 21, 2008 – 3:17 pm
- Author:
- By Dave
I recently tried to install a PHP PECL extension on a server I manage, when I received this error: [root@xxxx PDO-1.0.3]# pecl install pdo downloading PDO-1.0.3.tgz … Starting to download PDO-1.0.3.tgz (52,613 bytes) ………….done: 52,613 bytes 12 source files, building running: phpize Configuring for: PHP Api Version: 20041225 Zend Module Api No: 20060613 Zend Extension Api No: 220060519 /usr/local/bin/phpize: /tmp/pear/temp/PDO/build/shtool: /bin/sh: bad interpreter: Permission denied Cannot find autoconf. Please check your autoconf installation and the $PHP_AUTOCONF environment variable is set correctly and then rerun this script. ERROR: `phpize’ failed [root@xxxx PDO-1.0.3]# After some searching, I figured out this is because I had set /tmp to noexec to keep any intruders from executing files from this directory. I suspect the same error will occur with any PECL extension installation. I temporarily turned it off with the command: mount -oremount,exec /tmp Now PECL installs extensions fine. Don’t forget to reenable noexec when….
Categories: Configurations,Linux,Shell
Tagged: pecl, PHP, sysadmin
- Published:
- November 13, 2008 – 12:39 pm
- Author:
- By Dave
I recently took upon the task of setting up a presentation display in the lobby of our building. This display had previously used an old computer running Windows 2000, and displayed a fairly simple PowerPoint presentation with a few frames, mostly a schedule for anyone coming into the building. We did a renovation and this display moved from a desk to on the wall. Therefore we needed to figure out a way to drive this display. We had 3 main options: Run the VGA cable upstairs to a room where the PC would sit. Purchase an expensive display driver box that could show PowerPoint along with other things like RSS feeds and video streams. I quoted this out and it was about $1800 for this fancy box. Install a small computer behind the display and use that to drive the presentation. I decided to purchase a FitPC Slim to drive….
Categories: Configurations,Other Technology,Shell,System Administration,Ubuntu
Tagged: display, lobby, power point, powerpoint, Ubuntu
