Re: HP "Autoraid" Performance

alcesteatxmissiondot_at_com.or.net wrote in message news:<bvidqr$kso$2_at_terabinaries.xmission.com>...
> Recently got an HP VA 7110 Disk Array with ten disks to run a
> development database on. This time around, I'm going with the
> "stripe and mirror everything" philosophy. When the HP tech was showing
> me the system, I was given the choice between Raid 1+0 and "Autoraid."
>
> At first I assumed this was a funny name for RAID 5, but it turns out
> that no, it was more than that. It seems to be a system that uses
> either a raid 1+0 or a raid 5 with an additional parity area, depending
> on the disk access characteristics.
>
> Here's a paper that talks about it...not sure how current the information is:
>
> http://www.hpl.hp.com/research/ssp/papers/Voigt1998.pdf
>
> The information I can find touts the system's performance over RAID 5, but
> I'm not finding any data that compares it for OLTP databases against
> a striped and mirrored configuration.
>
> Anyone used this or looked at it? What do you think?
>
> Jer Smith

It is _very_ dependent on configuration and patches. I have one older machine that just runs so bad and I don't have time to sit down and install glance and futz around and figure out why and futz with the working set. Easier just to replace the autoraid with hand-me-downs from the bigger machines as they get upgraded. Development machines seem to get that a lot, eh?

Every installation I've seen seems slow, although it is likely that the installations I've seen are skewed towards "not well administered", since they are usually packaged apps installed by those who wouldn't care about such things as disk and tablespace layouts. And I've even seen it replaced by RAID-5 arrays with better performance. Sometimes "just throw hardware at it" is a reasonable choice.

jg

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