I reinstalled the site's svr020 UI on Saturday. This involved an incredible amount of pain related to the bizarre inability of SL4 to properly install GRUB on a linux software RAID partition. Although the machine would install absolutely fine, on reboot it would just halt after the GRUB prompt.
In the end, after tearing my hair out several times (I was working from home on Friday) and trying as many tricks as I could (I even DBANed the disks), I had to retreat from running software RAID1, and fallback to running only on one of the SCSI disks. (As an
That finally gave me a base SL4 install I could work with.
After that, the installation of the SL4 32bit UI was easy - running through cfengine (one little caveat was that the gsisshd restart would kill off the normal sshd on port 22, so that has been disabled).
Then I found that job submission didn't work, because it relies on a 32bit python/C module and the default python is 64bit now. The advice on ROLLOUT was to have a 32bit python higher in the path than /usr/bin/python. This seemed rather bad advice to me, as we'd like to really have 64 bit python - it is a 64 bit system after all! So, instead I decided to change the magic bang path to specifically reference /usr/bin/python32. Initially I tried to use cfengine's editfiles facility to do this. However, anything which is not a completely trivial modification is rather horrendous to do in cfengine (it reminded me of ed, actually), so I eventually abandoned this, and instead wrote a 3 line perl special in the cfengine script sources, and this is called after the RPMs are installed. (In addition to changing the python interpreter it disables the tk graphical interface, for which we don't have any users anyway.)
Finally, I upgraded ganga, and this went fine - ganga runs quite happily with 64 bit python (normally this wouldn't deserve special note, but in the grid world flowers and champagne are in order).