Scott Silva wrote: > 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. > > I'm not looking for total reliability. I am building a low budget file/backup server. I would like it to be fairly reliable with good performance. Basically if 1 drive fails, I would like to still be up and running, even if it requires slight reconfigurations (ie recreating the swap partition). If 2 drives fail, I would like to still be able to be up and running assuming I wasn't unlucky enough to have 2 drives fail in the same mirror set. If 3 drives fail, I'm pretty much SOL. The most important thing is that I can easily survive a single disk failure. Russ