>Message: 67 >Date: Fri, 11 May 2007 11:40:25 +0800 >From: Feizhou <feizhou at graffiti.net> >Subject: Re: [CentOS] Re: Anaconda doesn't support raid10 >To: CentOS mailing list <centos at centos.org> >Message-ID: <4643E5A9.3030302 at graffiti.net> Feizhou wrote: <snip> >The SCSI drive: >Spindle Speed 15000 rpm >Average latency 2.0 msec >Random read seek time 3.50 msec >Random write seek time 4.0 msec >The SATA drive: >Spindle Speed 7200 rpm >Native Command Queuing Y >Average latency 4.16 msec >Random read seek time <8.5 msec >Random write seek time <10.0 msec >Maximum interface transfer rate 300 Mbytes/sec >Compare to a 10K scsi drive: >Spindle Speed 10,000 rpm >Sustained data transfer rate 80 Mbytes/sec. >Average latency 3.0 msec >Random read seek time 4.9 msec >Random write seek time 5.4 msec >Maximum interface transfer rate 320 Mbytes/sec The above specifications are about Performance. If maximum Reliability is the goal, look at the MTBF in the specifications. If the Design Engineers have done their job, and the Manufacturing Engineers maintain high Quality Control, the result should be a quality component. As has been pointed out in this thread, RAID is *not* a substitute for backups. RAID is intended to keep the box up and running. Valuable data should always be stored off site, in removable drives, or via the WAN. Lanny