GU Physics DokuWiki it:blog

it:blog:03_04_2012_14_54

2012-04-03T14:56:08+01:00

It seems sometimes the internal MATLAB paths for the toolboxes can go astray for users - need to go in and correct this manually. Seems to affect the Statistics toolbox a lot.

it:blog:04_09_2013_17_00

2013-09-04T17:09:04+01:00

The array_multisort function in php allows you to sort several arrays at the same time. How it works is: * Sort first array by key value (depending on arguments) * If there are any identical keys in the first array, sort these by the keys in the second array (assuming it is specified) * etc.

it:blog:06_02_2014_18_35

2014-02-06T19:05:21+01:00

Ubuntu 13.10 (and possibly 13.04) seem to have a problem with self-signed certificates when authenticating to wireless radius servers (i.e. the GUPHYSICS wifi). This is discussed in a variety of places:

it:blog:07_03_2013_18_36

2013-03-07T18:43:32+01:00

OSX Mountain Lion (10.8) seems to change the order of the MAC addresses presented to flexlm licence processes. There is a page about various problems at the Mathworks website: Why am I unable to launch MATLAB after upgrading to Mountain Lion? At the bottom of the page it gives the command to run to determine which address the licence process is seeing:

it:blog:09_07_2012_18_52

2012-07-18T15:44:22+01:00

N.B. Gave up on this - taking too much time and effort for something that would require some command line admin anyway - such as the mailer configuration. Will go back to purely standard setup on Debian like existing servers. is really useful!

it:blog:10_01_2013

2013-01-11T00:01:41+01:00

Yumex complains that it can't download stuff and bombs out. Even if yum proxy has been set and yum is working. To fix, edit /etc/yumex.conf and add the proxy in: proxy = "http://your.cache.address:port" The quotes are required! Some information about the grub font error at

it:blog:11_04_2013_22_42

2014-02-19T16:39:35+01:00

work. List of colors [sic] , , , , , , , , , , , , , , , . There is a toolbar control as well.

it:blog:11_06_2013_18_50

2013-07-31T17:50:43+01:00

Networking (firewall related) Some of the older debian servers are firewalled using a command in the /etc/network/interfaces file to load the iptables rules. For some reason this breaks the file on upgrade to Debian wheezy and the network interfaces don't come up on boot. To fix, comment or remove the line:

it:blog:12_03_2014_18_26

2014-03-13T16:58:17+01:00

There are several ways to have a linux box email you when someone logs in to it. Most of these use a script in either the local profile files (for individual users) or the system-wide profile (and/or in sshrc). Another nice way is to use the pam authentication system to do the job. A setup is given at:

it:blog:13_06_2013_17_05

2013-06-14T17:42:53+01:00

Proxmox uses postfix as its MTA. To configure this to send email via smarthost run dpkg-reconfigure postfix For general type we want Satellite SMTP server - usual Mailbox size - could use the suggested 51200000 here - should be more than big enough seeing as nothing should be ending up in the system mailbox anyway.

it:blog:14_01_2013

2013-01-22T12:37:04+01:00

Because I always forget about this one... For Server 2003 (and 2008) run gpedit.msc and change the key Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\Shutdown: Allow system to be shut down without having to log on

it:blog:14_03_2013_22_48

2013-03-15T12:08:48+01:00

Often the Windows update shield in the system tray won't appear when you RDP into systems. A fairly reliable trick seems to be the following: * Stop the Automatic Update service ( net stop wuauserv from the command line ). * Set the NextFeaturedUpdatesNotificationTime key ( located at HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\ ) to a date and time slightly ahead (say a minute or two) of the present. * Start the Automatic Update service ( net start wuauserv )…

it:blog:14_06_2013_16_40

2013-06-14T16:58:21+01:00

After properly configuring postfix on the Proxmox hosts to send email, emails to root were noticed daily: /etc/cron.daily/mlocate: /usr/bin/updatedb.mlocate: `/var/lib/mlocate/mlocate.db' is locked (probably by an earlier updatedb) run-parts: /etc/cron.daily/mlocate exited with return code 1 After logging on to one of the boxes, killing (-9) the updatedb process and running it with verbose on:

it:blog:17_08_2012_15_01

2012-08-17T15:11:19+01:00

Procedure * Create a storage area that both clusters can see (e.g. NFS on freenas box) * Backup VM from 1.9 system to backup area. * SSH to backup area and move backup tgz file from root of share (where 1.9 backs up) to dump directory (should have been created by connecting 2.1). * Restore from backup in 2.1 (may want to keep the same VMID, to avoid inconsistent disk image numbers) * Change hardware if required (VM won't start if pointing to non-existent CD image, change network to ap…

it:blog:18_05_2012_16_14

2012-05-18T16:57:07+01:00

This should be a five-minute job, and if Dell used the standard mountings it would be. Guess what... The T1500 has the mounting holes in the standard places for a LGA 1156 socket, but has screw bosses in these holes, presumably held there by a backing plate behind the motherboard. The stock heatsink screws into these with captive screws - springs hold the bracket down. In theory if the bosses were removed a standard heatsink would clip in, but this would require the motherboard to be removed. A…

it:blog:19_07_2012_19_47

2012-07-20T17:17:25+01:00

Proxy In addition to the web interface setting (for the cluster), need to configure aptitude as well. Add to somewhere appropriate (e.g. /etc/apt/apt.conf.d/70debconf) Acquire::http::Proxy "http://wwwcache.gla.ac.uk:8080"; Acquire::ftp::Proxy "http://wwwcache.gla.ac.uk:8080"; Time Have to set up NTP on each system as before. Edit /etc/ntp.conf to add:

it:blog:20_01_2013

2013-01-20T01:21:43+01:00

According to (v=ws.10).aspx this should be simple. Trying it on a Server 2003 VM (that had been converted from Virtual Server 2005) didn't give the options of the other HALs. The answer is at - use the command line devcon.exe tool and the .cmd script at .

it:blog:20_03_2012_16_28

2012-03-20T16:33:39+01:00

When trying to start EVO it fails with a “Cannot start application” have a look at the detailed error info. There may be something about not being able to connect to the .jnlp file on the web. If so, have a look at the proxy setup of the browser. Fixed one system/account today by changing Firefox proxy from “system” to the normal autoproxy address.

it:blog:20_06_2013_14_50

2014-02-19T16:37:12+01:00

Examples/Usage (Copied from ) NOTE that the default configuration uses \$ (dollar signs) to delimit TeX formulas. This may cause trouble if you have \$ characters in any pages. The default configuration also lets you escape the dollar signs, however, by changing them to \$. This should correct any problems you might have.

it:blog:21_02_2013

2013-02-21T19:21:15+01:00

In our case, wondering where that cannot create Microsoft.SMS.Client object 800A01AD error comes from... Sometimes you need to let ccmsetup.exe do it's thing when joining systems to the domain.

it:blog:22_01_2013

2013-08-07T15:44:24+01:00

It can sometimes be difficult to get Windows systems to shut down reliably using an ACPI signal (either the power button for a physical system, or an equivalent signal from a virtual machine hypervisor). Generally you find after the system has been on for a period of time, the first ACPI signal merely wakes up the screen. On a physical system this makes some sense - it shows you the system is in fact on already. To turn a physical system off you just press the power button again. For a virtual s…

it:blog:23_07_2012_18_41

2012-07-23T18:47:56+01:00

Way to change primary interface - edit /etc/hosts to change ip address returned when cman does lookup of system hostname. e.g. 127.0.0.1 localhost.localdomain localhost 192.168.40.6 Hildasay.physics.gla.ac.uk Hildasay pvelocalhost # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters ff02::3 ip6-allhosts

it:blog:23_07_2014_18_53

2014-07-23T19:11:10+01:00

File download The links on the cadsoft page were broken when I did this. The licencing setup files were found at: The later version directories only contain the lichostid files (also included in the full install). You do need this for the hostid - it doesn't just work off the MAC address!

it:blog:25_04_2012_16_14

2012-04-25T18:14:03+01:00

Install Java Needs to be the Oracle JDK. Download the .bin file and make it executable. Create appropriate directory, change to it and run the .bin file. update-alternatives --install "/usr/bin/java" java" "/usr/lib/jvm/jdk1.6.0_31/bin/java" 1 Creates link for java in /usr/bin/

it:blog:28_03_2012_18_42

2012-03-28T18:47:01+01:00

Migrating files in media directory under data works fine. Suspect copying over the pages directory into the new namespace would have worked ok as well, if namespace is flat and links are relative. For hierarchical structures there will be a lot of link editing to do, but that's almost always the case anyway. And you need to browse all the pages to get them indexed anyway.

it:blog:28_06_2012_17_08

2012-06-28T22:03:38+01:00

The latest versions of the Uni Powerpoint templates have slightly different RGB colours from the original guidelines. Looks like a improvement snuck in without telling anyone. Colour R G B Old blue 0 53 95 New blue 0 33 60 Old SciEng 119 120 0 New SciEng 91 101 27 For the new SciEng template the logo remains the same. For the generic Uni template the logo has been altered so the shield is the same shade as the new blue. I've approximately replicated…

it:blog:28_06_2012_20_47

2012-06-28T21:22:57+01:00

LDAP server package is slapd. LDAP command-line stuff gets installed along with it. First database is set up automatically - only requirement is admin password. Root DN is taken from host IP domain name - so get dc=physics,dc=gla,dc=ac,dc=uk if not careful. And with OpenLDAP there's no easy way to delete databases.

it:blog:29_03_2012_16_05

2012-03-29T16:06:35+01:00

Interesting problem using the DokuWiki sidebar plugin and headings in the sidebar markup. If you put headings in the table of contents for the page seems to pick these up in preference to the headings in the actual page. Solution - don't use headings in the sidebar.

it:blog:30_04_2012_18_00

2012-04-30T18:15:57+01:00

Well, that was odd. Managed to get WebCal ( ) to work (after realising it doesn't hook into the DAViCal database at all - it's a completely separate admin account, user accounts etc). After creating user, couldn't add calendars to them. Eventually tracked it down to utils/helper.php and the encode and decode functions which were retrieving $iv of the wrong lengths - saw 21 and 24 bytes. After putting code in to watch the variables creat…

it:blog:30_07_2012_22_40

2013-07-31T17:55:38+01:00

Try highlighting the text in these.

 block:


*filter

# This will allow all loopback (lo0) traffic and drop all traffic to 127/8
# that does not use lo0
-A INPUT -i lo -j ACCEPT
-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT

#  This accepts all already established connections
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

# This allows all outbound traffic
-A OUTPUT -j ACCEPT



it:blog:31_07_2012_17_15
2012-07-31T18:05:07+01:00
Server setup

Debian 6 (advanced install, static IP, base system only)

Filesystem – / on one disk image, /export0 on another (which should maybe be mounted with the no execute option for safety?).

Additional packages:

	*  ssh (both for remote admin and for https)
	*  subversion (obviously)
	*  apache2 (to serve svn over http)
	*  libapache2-svn (installs the mod_dav_svn and mod_authz_svn apache modules, if they haven’t been installed already)