Re: UDB RAID

["Christopher W. Curtis" <ccurtis aet-usa com>]

Jaap Hogenberg wrote:

> I think a RAID 5 setup should do the trick for you.
> It's faster than RAID 0+1 (at least for writing)  and
> will get you more disk space (66 % on 3 disks vs 50 % for RAID 0+1)

Okay, thanks.  I was concerned that the 166AXP would be struggling under
the parity load.  It's not really a high volume service, but I didn't know
what kind of load it would require.  I'd prefer to have that 1.5GB
available.

> BTW  RAID 0+1 (=mirrored sets of striped disks) is quite hard to do with
> only 3 disks , 4 would be minimal.

That's what I thought, but didn't know if 0+1 was different than 1+0 and
didn't understand how mirroring would work with three disks, etc.  It
looked like I wanted RAID 5, but the CPU usage concerned me.

> As this is a multia , you possibly have only 1 scsi interface , so for
> performance, this might well be the bottleneck with a raid setup.

I suspect it might be as well.  It's all SCSI-10.

As for additional backup, I also have tape so it's not a SPOF.  I'm not
really sure what I'm going to put on here, but I suspect it will be used
primarily for CVS data.  This UDB has 72MB RAM so I guess that's another
negative for mirroring due to the page cache.

Thanks for the help!
Chris