Lucky me, someone has installed a server and got it running with the best intentions, but leaving me a headache.
We have a simple p520 with 4 disks. 2x145Gb & 2x300Gb. The smaller disk pair have been built into a VIO mirrored rootvg, and quite right too.
The other two disks form a volume group each (VIO storage pools). The plan was to ensure that disk allocated to the LPARs would be made in pairs, one from each user-volume group so that we would be confident at the LPAR that the hdisk definitions presented would be from different real media. The problem I now have is that we are adding more real disk (another 16x300Gb in a separate CEC) and add more LPARs.
So, should I create more volume groups on the VIO server (storage pools) on a one-disk-one-pool rule, or should I approach this another way. What would be nice would be a way to present the LPAR with a single device made from a mirror at the VIO server and enforcing strictness on the VIO server to make sure that the mirrors are on different real disks.
I feel that if/when we have a disk failure, I'm going to have a huge mess of failed hdisks in the various LPARs we will have and a huge overhead in logging and maintaining disk separation for all these LPAR hdisks and mirrors making sure that LPAR mirrors do not inadvertently end up on the same real disk as the primary copy, albeit a different hdisk that the LPAR sees.
Big question/headache I know. Any suggestions?
Robin
Liverpool/Blackburn
UK
02-02-2011
