Experiment Software

Experiment software is typically installed by a privilaged user via a grid job. The user will have write access to the appropriate part of the software installation area, allowing them to add to and amend software at their convenience.

epgce3

Experiment software is installed in the /egee/soft/ directory. The original directory resides on a 177 GB disk local to epgce3. This is no longer large enough, so software is in the process of being moved to a 4.6 TB disk ( /disk/f15d/ ) on epgsr1.

Moving software to epgsr1

It is a simple task to copy the software available to the epgce3 WNs to epgsr1:

  1. Mount epgce3:/egee/soft somewhere convenient on epgsr1 (for example /tmp/soft)
  2. Copy the software from epgsr1:/tmp/soft to epgsr1:/egee/soft
  3. Unmount epgce3:/egee/soft from WNs and mount epgsr1:/egee/soft instead
  4. Clean up

Mount epgce3 on epgsr1
Start by making sure that epgsr1 has permission to mount epgce3:/egee/soft by editing the files epgce3:/etc/exports and epgce3:/etc/hosts.allow. In order for the export rules to be updated the command exportfs -r must be issued. Don't forget to use the no_root_quash modifier in the exports file to allow full root access!

epgce3:/egee/soft will now be available for mounting on epgsr1 with the following command:

mount epgce3:/egee/soft /tmp/soft

It's availability can be confirmed with a simple df -h

Copy software

Very simple, use cp -a to copy the appropriate directories from one disk to another. Note that scp should not be used because this does not preserve soft links!

Mount new filesystem on WNs
The WNs automount /egee/soft/ as defined in local copy of /etc/fstab This was updated to reflect the new software disk. New /etc/fstab files were distributed using rdist. ( look at different fabric management for future). /egee/soft/lhcb was unmounted and then remounted. As no LHCb jobs were running on epgce3 it was safe to stop the long and short queues while remounting the software area.

Note: tune2fs was used to rename filesystems on epgd01, which carried different labels to the other WNs

Cleanup
The long and short queues were restarted on epgce3. The epgce3:/egee/soft directory was unmounted from epgsr1.

epgce4

Complete mystery... for now!

-- ChristopherCurtis - 09 Jul 2009

Topic revision: r3 - 27 Jul 2009 - 14:21:13 - ChristopherCurtis
 
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