> -----Original Message----- > From: redhat-list-bounces@xxxxxxxxxx [mailto:redhat-list- > bounces@xxxxxxxxxx] On Behalf Of kenwardc > Sent: Thursday, August 19, 2004 10:48 AM > To: 'General Red Hat Linux discussion list' > Subject: RE: RAID on RedHat 3 ES > > Hi Mike > > Yep - the box is a Dell 1650 with Perc3 RAID on daughterboard so > should be good for building the spare. If you have a hardware raid controller the OS doesn't matter, as long as the controller is supported. Pretty decent description of various raid levels. http://www.acnc.com/04_01_00.html in short: Raid 0 (stripe): fast I/O, no fault tolerance. (min. 2 disks) Raid 1 (mirror): same I/O as single disk, fault tolerant (2 disks) Raid 5 (stripe + parity): high read I/O, med write I/O, fault tolerant (min 3 disks) Raid 10 (mirror + stripe) : high overall I/O, same fault tolerance as raid 1. (most expensive $/GB) For a mail server, assuming you are not going to host a ton of users on it in general RAID 1 serves best (given that you only have 2 drives). If you can fork out money for 2 or 3 more drives I would go RAID 5 + 1 spare, maximizing fault tolerance and useable disk space. Stripe is a definite no if you care about the uptime of the system and recoverability from a disk failure without having to resort to tape backups etc. -T > > Drives will be around 2 x 36 Gbyte so not too huge either. > > Regards > Chris > > > -----Original Message----- > > From: redhat-list-bounces@xxxxxxxxxx > > [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Michael Wimpee > > Sent: 19 August 2004 18:39 > > To: General Red Hat Linux discussion list > > Subject: Re: RAID on RedHat 3 ES > > > > On Thu, Aug 19, 2004 at 04:02:16AM -0500, Steve Phillips wrote: > > > > > > Software RAID comes with a preformance hit that with todays > > processors > > > you probably will never notice. > > > > > > RAID1 would be ok, if you are after rock solid redundancy then > > > purchase another drive as a hot spare (and if your really > > keen, try to > > > ensure that the drives are nto from teh same production batch) > > > > > Be aware however, that under heavy I/O, a failed disk may take a > > *really* long time to rebuild under software RAID. We saw > > >150MB/s using four SCSI drives under software RAID 5, but > > when testing rebuild speed, normal disk I/O caused the > > rebuild time to get pushed out towards infinity. It wouldn't > > have worked well in our situation so we went with a hardware > > RAID controller. > > > > Mike Wimpee > > > > > comments like "dont know if it is really effective" are kinda > wishy > > > washy, effective against what ? was he saying that a single drive > > > system would have greater redundancy than a mirrored setup > > ? what sort > > > of effect was he commenting on ? > > > > > > the preformance hit you will see will also depend on how many > users > > > and how busy you expect the server to be - also, buying > > 5400rpm drives > > > will probably not help much, try and get reasonably fast > > drives with a > > > reasonable ammount of cache ram. > > > > > > if you are after reliability only then there is no point to stripe > > > > (infact, some people claim that software stripes actually > > slow things > > > down over say - RAID 10) > > > > > > > > > -- > > > Steve. > > > > > > On Thu, 19 Aug 2004, kenwardc wrote: > > > > > > >Hi All > > > > > > > >Someone said to me today they didn't know whether RAID on > > Linux was > > > >very effective. Can someone tell me whether it's still > > worth RAIDing > > > >drives on Linux? I'm building a new mail server and I > > wanted to put > > > >in RAID 1 just in case of problems with drives etc. down the > line. > > > >Any advice appreciated. > > > > > > > >Also, provided the answer to the question is YES, is RAID > > 1 the best > > > >for a mail server or should I be looking at striping? I'm > > obviously > > > >not looking for the greatest speed but want absolutely reliable > > > >redundancy. > > > > > > > >Regards > > > >Chris > > > > > > > > > > > > > > > >--- > > > >All messages scanned by AVG 7.0 Anti-Virus scanner and > > TGIS Anti-Spam > > > >Firewall. > > > > > > > > > > > >-- > > > >redhat-list mailing list > > > >unsubscribe > > mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > > > >https://www.redhat.com/mailman/listinfo/redhat-list > > > > > > > > > > > > > -- > > > redhat-list mailing list > > > unsubscribe > > mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > > > https://www.redhat.com/mailman/listinfo/redhat-list > > > > > > > > > -- > > redhat-list mailing list > > unsubscribe > mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > > https://www.redhat.com/mailman/listinfo/redhat-list > > > > > > > > --- > All messages scanned by AVG 7.0 Anti-Virus scanner and TGIS Anti-Spam > Firewall. > > > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
