lkml.org 
[lkml]   [2010]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: BUG:write data to degrade raid5
Kristleifur Daðason schrieb:
> On Fri, Mar 19, 2010 at 6:20 PM, Joachim Otahal <Jou@gmx.net
> <mailto:Jou@gmx.net>> wrote:
>
> jin zhencheng schrieb:
>
> hi;
>
> i use kernel is 2.6.26.2
>
> what i do as follow:
>
> 1, I create a raid5:
> mdadm -C /dev/md5 -l 5 -n 4 /dev/sda /dev/sdb /dev/sdc /dev/sdd
> --metadata=1.0 --assume-clean
>
> 2, dd if=/dev/zero of=/dev/md5 bs=1M&
>
> write data to this raid5
>
> 3, mdadm --manage /dev/md5 -f /dev/sda
>
> 4 mdadm --manage /dev/md5 -f /dev/sdb
>
> if i faild 2 disks ,then the OS kernel display OOP error and
> kernel down
>
> do somebody know why ?
>
> Is MD/RAID5 bug ?
>
>
> RAID5 can only tolerate ONE drive to fail of ALL members. If you
> want to be able to fail two drives you will have to use RAID6 or
> RAID5 with one hot-spare (and give it time to rebuild before
> failing the second drive).
> PLEASE read the documentation on raid levels, like on wikipedia.
>
>
> That is true,
>
> but should we get a kernel oops and crash if two RAID5 drives are
> failed? (THAT part looks like a bug!)
>
> Jin, can you try a newer kernel, and a newer mdadm?
>
> -- Kristleifur
You are probably right.
My kernel version is "Debian 2.6.26-21lenny4", and I had no oopses
during my hot-plug testing one the hardware I use md on. I think it may
be the driver for his chips.

Jin:

Did you really use the whole drives for testing or loopback files or
partitions on the drives? I never did my hot-plug testings with whole
drives being in an array, only with partitions.

Joachim Otahal

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-03-19 19:39    [W:0.775 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site