>
>
> 1. SAP Data: RAID5
> 2. OS,SWAP space,OS Log file: RAID1
> 3. SAP Log file,SAP and Oracle EXE files: RAID 5
>
> What do you think?
> Regards
> Bob
DON'T do nr. 1!
DON'T do nr. 3 - if "SAP Log file" refers to the online redo log files of the database.
For a lengthly discussion of why not to go for RAID5 you may check [http://www.miracleas.com/BAARF/] and the articles around there.
Basically what you get with RAID5 is:
- far slower write performance
- not the best read performance
- a false sense of data security (I've seen way too many systems - Oracle as well as MaxDB/liveCache - where a disk was replaced and the RAID controller 'repaired' the missing data; the next thing required was to get the latest backup out!)
Also quite common: todays databases use checksums to perform consistency checks on the pages they write and read to the disks. There are so many customers reporting a corruption (detected by this very checksum-method) and insisting that it must be a bug in the database software, since the RAID5 monitor shows all lamps in bright green.
In fact, most of these cases still turn out to be storage system errors.
So if this were my database, I wouldn't go for RAID5 at all. To me this really is something that might work OK if you have something like a fileserver but for databases - no way!
Hope that helps to find the right decision...
regards,
Lars
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