Ruslan Sivak spake the following on 5/7/2007 1:44 PM: > Toby Bluhm wrote: >> Ruslan Sivak wrote: >>> Ross S. W. Walker wrote: >>>>> -----Original Message----- >>>>> From: centos-bounces at centos.org >>>>> [mailto:centos-bounces at centos.org] On >>>>> Behalf Of Ruslan Sivak >>>>> Sent: Monday, May 07, 2007 12:53 PM >>>>> To: CentOS mailing list >>>>> Subject: [CentOS] Anaconda doesn't support raid10 >>>>> >>>>> So after troubleshooting this for about a week, I was finally able >>>>> to create a raid 10 device by installing the system, copying the md >>>>> modules onto a floppy, and loading the raid10 module during the >>>>> install. >>>>> Now the problem is that I can't get it to show up in anaconda. It >>>>> detects the other arrays (raid0 and raid1) fine, but the raid10 >>>>> array won't show up. Looking through the logs (Alt-F3), I see the >>>>> following warning: >>>>> >>>>> WARNING: raid level RAID10 not supported, skipping md10. >>>>> I'm starting to hate the installer more and more. Why won't it let >>>>> me install on this device, even though it's working perfectly from >>>>> the shell? Why am I the only one having this problem? Is nobody >>>>> out there using md based raid10? >>>> >>>> Most people install the OS on a 2 disk raid1, then create a separate >>>> raid10 for data storage. >>>> >>>> Anaconda was never designed to create RAID5/RAID10 during install. >>>> >>>> -Ross >>>> >>>> >>> >>> Whether or not it was designed to create a Raid5/raid10, it allows >>> the creating of raid5 and raid6 during install. It doesn't, however, >>> allow the use of raid10 even if it's created in the shell outside of >>> anaconda (or if you have an old installation on a raid10). >>> I've just installed the system as follows >>> >>> Raid1 for /boot with 2 spares (200mb) >>> raid0 for swap (1GB) >>> raid6 for / (10GB) >>> >>> after installing, I was able to create a raid10 device and >>> successfully mount and automount by using /etc/fstab >>> >>> Now to test what happens when a drive fails. I pulled out the first >>> drive - Box refuses to boot. Going into rescue mode, I was able to >>> mount /boot, was not able to mount the swap drive (as to be expected, >>> as it's a raid0), was also not able to mount the / for some reason, >>> which is a little surprising. >>> I was able to mount the raid10 parition just fine. >>> Maybe I messed up somewhere along the line. I'll try again, but it's >>> disheartening to see that a raid6 array would die after one drive >>> failure, even if it was somehow my fault. >>> Also assuming that the raid5 array could be recovered, what would I >>> do with the swap partition? Would I just recreate it from the space >>> in the leftover drives and would that be all that I need to boot? >>> Russ >>> >>> >> >> Russ, >> >> Nothing here to help you (again - :) just looking down the road a >> little. If you do get this thing working the way you want, will you be >> able to trust it to stay that way? >> > Well, it's been my experience, that in linux, unlike windows, it might > take a while to get things the way you want, but once you do, you can > pretty much trust it to stay that way. > So yea, this is what I'm looking to do here. I want to set up a system, > that will live after 1 (or possibly 2) drive failures. I want to know > what I need to do ahead of time, so that I can be confident in my set > up, and know what to do in case disaster strikes. > > Russ If you have the hardware, or the money, you can make a system pretty durable. But you get to a point that the gains aren't worth the cost. You can get a system to 3 "9's" fairly easy, but the cost to get to 4 "9's" is much more. If you want something better than 4 "9's", you will have to look at clustering, because a single reboot in a month can shoot down your numbers. If you want total reliability, you will need hot spares and a raid method that builds quickly, and you will need regular backups. -- MailScanner is like deodorant... You hope everybody uses it, and you notice quickly if they don't!!!!