Re: raid level

Gijs Wuyts wrote in message <35b4978f.3064156_at_news.skynet.be>...
> I'm about to decide on a Oracle DB server, with 5-10 webclient
>connections.
>
>What would be the best solution, RAID 5 is too slow,

Is it? Have you tested it?

RAID5 can be much slower on *writes*, but is usually as good as striped disks on *reads*. The fault-tolerance is good for relatively low cost. Do a bit of testing, as all systems are different. You might find you can live quite happily with RAID5. If not, pull some of the heavily written sections of your system off on to mirrored drives - redo, temp, etc., and you still might find RAID5 suitable.

>Raid 1 is fast
>enough, but I would need to spread the different DB-parts ( logfiles,
>rollback-segments, data files,... ) on different disks/controllers.

Yep, but RAID0+1 would probably give you even more of a speed up, especially if you do lots of sequential reading and writing.

As regards spliting your db, the same rules apply to RAID systems as they do to individual disks - aim to balance the I/O. If this means setting up mutiple RAID sets (and maybe with mixed RAID levels - see above) then do it. Ditto multiple RAID adapters and power supplies.

Think the whole process through before you start, and get as much data on the hardware as you can. Test, and test again on a system representative of what you arr trying to achieve - try and blag a few loan systems, or go to the vendors 'labs' with you db - that's what I do.

MotoX.

>Anybody with experience on this ?
>
>Probably we'll go for brand names DELL or COMPAQ.
>Any drawbacks from those ?
>
>Gijs
Received on Wed Jul 22 1998 - 03:00:16 CDT