Hi
We have just invested in a Fibre Channel SANs and several FC attached ESX servers (brillant product, just love vmotion and virtual center) and are playing with Virtualised Openafs Fileservers. All is working very well except if we put to many volumes on a server at which point "vos listvol" takes a very long time to return.
If we have say 5000-7000 volumes (about 50Gb) on a vice partition performance is equivalent to hardware server. At 10k volumes to 40k volumes 100-300Gb we have problems with vos listvol.
This is not a huge problem for us as we wanted to do more smaller machines any way to take advantage of the VM environment but it does make me wonder why this occurs.
What exactly does vos listvol do? does it scan the vice partitions and return all the volumes it finds (du -sh /vicepa takes a huge amount of time too so maybe this is a vm issue)? Is any network traffic exchanged with the DBs?
When we start vos listvol on the virtualised server with lots of volumes it just seems to stop working with the cpu usage for the afs process not jumping above 1-2%. An strace (available if anyone interested) shows the vos listvol is doing something (although very slowly).
If the virtualised server has less volumes cpu usage jumps up to 30-50% and every thing works.
The only thing effected seems to be vos listvol as accessing a volume stored on the server is quick (from user point of view). vos backup stuff all seems to work.
Hardware server with same number of volumes works OK.
SANS monitoring suggests there is not a data access issue on that side.
Not sure this is an AFS issue but any suggestion to help me understand why vos listvol is effected so badly apprepriated.
Cheers
Matt _______________________________________________ OpenAFS-info mailing list OpenAFS-info@openafs.org https://lists.openafs.org/mailman/listinfo/openafs-info
