MPU Meeting Tuesday 17th April 2012

LCFG Server Refactoring

Stephen is writing up the project, aiming for a May sign-off.

Simple KVM Service

While writing up the project for sign-off, Alastair had an idea about how to detect time slew on suspended guests: the hardware clock follows the time of the host (although it's perhaps a second out) whereas the normal clock doesn't; so one could compare the two and correct the time using ntpdate when a difference appeared.

Opinion varies as to whether NTP is necessary or advisable on KVM guests: it seems to keep a KVM guest's clock in sync, but some say that that changes when the host is heavily loaded.

Stephen suggested another look at the Sys::Virt perl module as the SL 6.2 version is significantly upgraded and now offers access to much more of the libvirt API.

Server Upgrades

The tobermory upgrade plan now contains post-upgrade debriefing comments.

The main problem exposed in the upgrade was the inability of the PE860 servers to handle it in a timely fashion: the master took several hours to reload the repository then the slaves took several hours to rebuild the profiles. It's also notable that while the virtual slave processed the complete cache-zapped rebuild far more quickly than the PE860s did, nevertheless they took the same time to process a routine stable release. It would seem that a rebuild from scratch is disk intensive whereas a stable release is far more CPU intensive. Since we do far more normal rebuilds than complete ones we think that servers with fast desktop-style CPUs are indicated to replace the PE860 slaves.

Server Hardware

Not much this week.

Miscellaneous Development

Perl AFS module
Stephen is still gathering information on its use in Informatics.
SL6 package conflict
There was an SL6 32 bit DICE level package conflict due to a package being built as i386 rather than i686. It's been sorted.
SL 6.2
is now the default in the lcfg layer. Stephen will warn Paul re DIY DICE.


Sleep with old monitors
Dell 790s now seem able to sleep and wake successfully even with old monitors with digital cables, so Chris has removed the restriction on their sleeping.
AFS build server
Stephen has been sorting out the build scripts for the OpenAFS build server. He's aiming to make them more maintainable and to make the system more self-maintaining.
Network problem on central
Alastair fixed it by removing the offending resource(s).

This Week

  • Alastair
    • respond to Stephen's query re perl-AFS module usage
    • try new BIOS on zip to test sleep
    • Bring Simple KVM project for signoff at May devel meeting
    • Ask services unit to create storage for northern/piccadilly at KB on evo
    • Call meeting re inventory project - too many people away just now, so having one-to-one meetings instead for now
    • Enable sqllite for yum repositories

  • Chris
    • writeup server h/w project so far on blob/wiki
    • replace cochin with SL6
    • server h/w project

  • Stephen
    • Bring LCFG refactor project for signoff at May devel meeting
    • Ask other units about their perl-AFS module usage (which functions etc)
    • Upgrade lochranza
    • Finish Theon work

-- AlastairScobie - 17 Apr 2012

Topic revision: r8 - 23 Apr 2012 - 13:55:23 - AlastairScobie
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