You should acheive maximum performance and uptime by mirroring two sets of
stripped volumes. You get all the write benefits of stripping and all the
read benefits of mirroring. Plus you never have any down time. When a volume
fails you put a new one in and resynch the databases.

This is the configuration being recommended by IBM. The problems we are
having is that our backups have a very small average file size, thus require
a lot of database activity and overhead during backup. What i want to really
know is with an average file size of 20-40K what kind of performance are
other sites seeing? If performance is breaking 1500Kb/s, how is you system
configured to acheive this? We are seeing performance in the 500-1000 Kb/s
range and this is very dissapointing.

Thanks
Paul SHields
pshields AT bnr DOT ca
Bell Northern Research



>Has anyone considered the usage of RAID disk arrays for the ADSM database
>volumes?  It would seem that the higher I/O rates possible from the RAID
>array would make an them an appealing prospect as well as the fact that
>some array controllers now come with a variable amount of disk cache memory.
>While the cache would probably prove useless for read data, a small amount
>of write cache space could prove itself to be very valuable when a few
>dozen clients are all running at the same time.
>
>The ability to dynamically rebuild data from a failed volume also strikes
>me as being useful as it could be used to avoid having to keep the database
>copy volumes (although you do suffer downtime while the volume is being
>rebuilt which you wouldn't suffer by using database copy volumes).
>
>---
>Keith A. Crabb         Keith AT UH DOT EDU
>University of Houston  Operating Systems Specialist +1-713-743-1530
>