Re: OnLine on RAID - what's the truth?

In article <44C2247EAFF4D011B0BD00805F85B09C0C6978FE@news.maricopa.gov>, Fred Prose <fprose@rocketmail.com> writes >From my experience, using raw disk and avoiding RAID is based upon two >things: >1) your hardware software >2) the superstitions of your local DBA! > >I had the opportunity to benchmark v 7.2 running on a 4 processor AIX box >from BULL (same hardware as RS6000). Cooked running on RAID 5 out performed >raw by 20%. > Read caching or write caching. Remember write cacing means that Online cannot guarantee the logical/physical logs make it to the disk before data/inded pages. Hence transaction logging will fail to work and you will not be able to recover after a hardware failure/OS panic... >Based upon what the local Informix people said, I wouldn't even have >considered this until I went to an optimization class and had fellow >students argue with the instructor. In their HP environment, cooked also >ran over raw - and it's a LOT easier to manage. > ?? Was the number of BUFFERS set high enough? HP will use all available memory for caching whereas Online is limited by the BUFFERS parameter... > -- David Williams Maintainer of the Informix FAQ Primary site (Beta Version) http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html I see you standin', Standin' on your own, It's such a lonely place for you, For you to be If you need a shoulder, Or if you need a friend, I'll be here standing, Until the bitter end... So don't chastise me Or think I, I mean you harm... All I ever wanted Was for you To know that I care