[CentOS] Anaconda doesn't support raid10

Mon May 7 20:44:29 UTC 2007
Ruslan Sivak <rsivak at istandfor.com>

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