Re: RAID technology

In article <3herna$aiv_at_socrate>, staccuc_at_riq.qc.ca (Sylvain Taccucci) wrote:

> I'm tinking of moving my system to a raid stripping disk system. But
> it's not obvious, when I read the tech manual, that it's easy to
> spread disk I/O on this technology. You don't know which part of
> witch table will be on each drive.
>
> Is anyone a suggestion on who spreading I/O on raid disk stripping
> system ?
>
> Where can I find information or recommendation about this technologie
>
> thank's

We use Both Sequents and OSF/1 disk arrays to provide striping. We have some large tablespaces (multiple datafiles, each 2gb, be very very wary of going over 2gb). The stripe sets are normally 6 x 2gb Disks, meaning that the datafile is distributed evenly over six disks. Performance is very good.

On OSF/1 we use LSM and ADVFS to provide the stripe sets (which we also mirror!) and have the table spaces in UFS partitions.

On Sequent we use PTX/SVM to stripe and mirror the disks, but use raw partitions.

It all takes more management, but the performance gains are there to be had.

-- 
Adrian Challinor
CEO, Osiris Consultants Ltd