Re: Hardware RAID vs OnLine Mirroring

Patrick Dwyer wrote: > > I have personally ran tests for performance using clarion arrays with NCR > hardware. > I compared RAID 1 (mirroring) with RAID 5 (parity). It cost about 15-20% of > performance > on inserts, as was about the same on reads. Remember, using raid you'll > hide the disks > from the Informix Partiioning. > > PaddyDD > > > I haven't tried the Clarion raid so I can't comment. Have you tried sticking a load of NVRAM in the way of the disks, that will significantly improve your writes. Some of the EMC devices can have 2GB of NVRAM ie you are really only ever writing to memory. The HDS raid I evaluated was faster as RAID5 with NVRAM than the same unit configured RAID1 without the NVRAM. OK the tests only put through 500MB of data in an hour but I think you get my point. -- Paul Watson # WF Software Ltd # It said run using Windows 95 Tel: +44 1436 674629 # or better in the manual Fax: +44 1436 678693 # so I used Unix www.wfsoftware.co.uk #