Gentoo Archives: gentoo-user

From: Mark Knecht <markknecht@×××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] RAID problems - Is udev at fault here?
Date: Sun, 16 May 2010 17:56:40
1 I have a newish high-end machine here that's causing me some problems
2 with RAID, but looking at log files and dmesg I don't think the
3 problem is actually RAID and more likely udev. I'm looking for some
4 ideas on how to debug this.
6 The hardware:
7 Asus Rampage II Extreme
8 Intel Core i7-980x
10 5 WD5002ABYS RAID Edition 500GB drives
12 The drives are arranged as a 3-drive RAID1 and a 2-drive RAID0 using mdadm.
14 The issue is that when booting gets to the point where it starts mdadm
15 and then about 50% of the time mdadm fails to find some of the
16 partitions and hence either starts the RAID1 with missing drives or in
17 the case of RAID0 won't start the RAID. For instance, /dev/md5 might
18 start with a failed partition, either /dev/sda5 or sdb5 or sdc5 isn't
19 found and the RAID is started. Once the problem has occurred I don't
20 seem to be able to fix it with anything other than a reboot so far.
22 Investigating dmesg when there is a failure I actually don't see that
23 the missing partition is ever identified and looking at the /dev
24 directory the partition isn't there either.
26 Personally I don't think the problem is with the drives as BIOS shows
27 me a table of the drives attached before booting and the 5 drives are
28 _always_ shown. If I drop into BIOS proper and use BIOS tools to look
29 at the drives I can _always_ read smart data and all drives respond to
30 DOS-based tools like SpinRite. It's only when I get into Linux that
31 they aren't found.
33 The problem hasn't changed much with different kernels from 2.6.32
34 through 2.6.34, nor do I see any difference running vanilla-sources or
35 gentoo-sources.
37 Currently I'm using udev-149 with devfs-compat and extra flags enabled.
39 Where might I start looking for the root cause of a problem like this?
41 Let me know what other info would be helpful.
43 Thanks,
44 Mark


Subject Author
[gentoo-user] Re: RAID problems - Is udev at fault here? walt <w41ter@×××××.com>