Re: Using oracle with RAID??

Hi Paul,  

This is what we (Oracle Support) suggest concerning availability (which is guaranteed by RAID5 for a disk failure) and best I/O throughput (which is better without RAID):  

Do not place redo logs on a RAID 5 logical device. The redo logs are the files with the highest write rate in Oracle. That's why we prefer to put redo logs on RAID 1 (mirrored disks). If you have to place redo logs on a RAID 5 logical device be sure that there's no write cache enabled. To recover all committed transactions, Oracle must write each committed tx in the redo logs. You'll get a lot of problems if a system fails and there's redo in the RAID write cache.  

Do not place archived redo logs on a RAID5 logical drive where also datafiles are on. If the RAID5 drive fails for whatever reason, you aren't able to recover because you lost the archive files. We prefer plaing the archived redo logs on RAID 0 disks.  

Use more than one RAID5 array to seperate I/O intensive daatfiles on different logical disks.  

Hope this helps
Best Regards

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