Re: Informix OnLine on RAID drives

> > Melody Fallah-Khair wrote: > > > > Hello, > > > > Has anybody experienced setting up Informix Online 7.x on > > RAID (Redundant Array of Independent Disks) disk drives? Any performace > > improvement or suggestion for how to set them up (RAID 0, 1, 2, ...6)? > * > > ******************************************** > RAID level 1 mirroring is done at the hardware level. This mean that the > dbms writes the row(s) to the dbslice and the array controller will > automatically write to the mirror. As a matter of fact UNIX does not > even know about the mirror, it is all handled by the array controller. > > I suggest however that you consider RAID 5. Using a 5 disk drive group > you only lose only 20% of the space as opposed to 50% with RAID 1. The > performance hit is on the writes however reading the data has no > consequences. > Hope this helps. We set up MTI raid 5 with Informix 7.11 and 7.23. I suggest that you look closely at how your database is performing first. In other words, check for extent problems, and try not to put a lot of write intensive spaces out on Raid 5 - we just did not have great success with that. We spent considerable time moving things on and off Raid and finally moved most of the application off raid and then striped out the spaces on regular scsi. I suggest that you sit down with your Raid vendor and get a good explanation of stripe depth, where to put logs, root and write intensive tables and how to really lay it out. We are slowly going to migrate back to a Raid 5 environment but are doing it with a bit more thought first. Good luck.. Ed (edbid@cobe.com)