Re: Hardware RAID vs OnLine Mirroring

Glyn_Balmer_at_erith@smtpgwy.supertension.com wrote: > > I have picked up on Dennis Harding's response regarding > Informix-OnLine and RAID. > > We are shortly upgrading our server, UNIX and OnLine engine to an ICL > (Fujitsu) Teamserver, SCO UNIX Openserver 5.0 and OnLine 7.2x. Our > intention (at this stage) is to use hardware RAID (5) (Mylex). We > shall have 5*4Gb disks, less 1 for RAID parity, giving 16Gb database > disk space. This will be raw disk. My questions are as follows :- (1) > Are there any known problems running OnLine 7.2x using raw disk and > hardware RAID ? (2) Would we be better off forgoing the hardware RAID > and using OnLine 7's mirroring ? > > Any comments, particularly in view of Dennis' comment ("In general, > Informix does not like RAID") would be very welcome. > > Regards > Glyn Balmer > I.T. Consultant > BICC Cables Limited > Erith Kent UK Depends on what you are doing, RAID 5 in a datawarehouse type environment is acceptable but not in OLTP or even anything approaching OLTP. The last time I used RAID5 on a live system all the updates where done overnight with the system being read-only during the day and it was very quick. However I also tested hardware mirroring it was a lot faster but it cost a lot more and the client decided they could live with RAID5. Unofficially UK ITS perfer hardware mirroring, or at least they did the last tiem I spoke to them. -- 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 #