Hugh E Cruickshank wrote: > From: Ross S. W. Walker Sent: May 25, 2008 08:56 > > > > Typically most vendors recommend a two-prong approach, keep the > > database data files on a RAID5/RAID6 type array and keep the > > log files on a RAID10 array. > > > > I can not comment on "most vendors" but for the PROGRESS RDBMS RAID5 > is definitely not recommended. It will work but you will see a > significant reduction in performance. We strongly recommend that our > clients go with RAID10 (as in RAID 1+0). In-house we only use RAID10. Ok, most vendors meaning MS, Oracle, Sybase. I am unfamiliar with PROGRESS (Postgresql variant?), but in my experience with the aforementioned they typically do all writing to the db log files, which is recommended to be kept on a RAID10, then when when transactions are checkpointed, they are written to the DB files. The software makes all attempts to keep the data written to the database files as linear as possible to make sequential access possible and dump/restore fast. This makes the log files write-mostly and the database files read-mostly and of course why the two different RAID types. Of course that really only pays if your databases are large enough to justify two separate storage systems. Right now my databases are small enough to be kept together with logs on a RAID10, but when they grow unwieldy I will move the databases off the RAID10 onto a RAID5/6/50/60 whatever and leave the log files on the RAID10. -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.