Re: Informix in the SAN environment

We just installed an EMC SAN hanging off of an IBM P650 AIX5.2. Yes we are using RAID 5, but our database is not that big and mostly OLTP. (Art, don't hit me!) Someone recommended that we use cooked files for simplicity. We tested this by loading/unloading an 18GIG database. Then we tested again using RAW with the same onconfig. RAW gave us about a 15% gain in speed, so we went with RAW. The SAN gave us about a 55% gain in speed over our 5year old MetaStore disk array. We are on IDS 9.40 so I think indices are detached by default. Physical and Logical logs each have thier own dbspace. We have a few 10GIG chunks and so far has been working fine. >>> Traveller2003 <vavavoom_th14@yahoo.co.uk> 06/24/04 06:33AM >>> Hi All , My question is:- Do all the practices mentioned over the years on this new group for disk layout's hold true still for performance on SAN's? I know NO RAID 5. No doubt you still get performance gains but at what price from the administration perspective. I admit it is a pretty open ended question but the idea is to get, hopefully a discussion with a number of views and ideas to use in the future for SAN environments if the "old" views are different. I also ask this question as SAN's technology is becoming more accessible ( Not to all though I know but I am lucky enough to have worked in a number of environments where they do have it). I am interested in a few that come to mind but other practices people want to discuss would be of great benefit as well. 1. Detached V attached indexes 2. Moving Physical Log and Logical Logs out of Rootdbs 3. Raw devices V cooked files using Vertias 4. Optimal Size of chunks related to version 9.4 as the 2 gig chunk limit has been removed. I also realise some of the above maybe a suck it and see type or personal preference question but I figure there are people out there who have experience of these on SAN's. Thank You Traveller2003 sending to informix-list