[CentOS] Kernel bug in software RAID?

Mon May 9 15:53:43 UTC 2005
Aleksandar Milivojevic <amilivojevic at pbl.ca>

Nigel Kendrick wrote:
> This but wouldn't cause my Proliant to fail to resync a RAID array after a
> reboot following the Centos-4 install would it?
> 
> I have just rebooted and get a message that the array is not clean, both
> drives are accessed and then for the second (IDE) drive I get:
> 
> Hde: drive not ready for command.
> 
> Then the system hangs.
> 
> The install went fine albeit very slowly - I presumed this was because the
> OS was being installed on a software RAID 1 pair and it was resyncing as it
> installed. Having said that I installed Centos-4 on a 300GB SATA RAID 1 pair
> on Friday and it whizzed through.

Installing on a software RAID1 (/dev/md*) that is something normal when 
doing an initial installation on an freshly defined RAID1.  Disks are 
syncing during the install (alt-f2 and type "cat /proc/mdstat"), and 
when you reboot they will continue with the syncing).  This shouldn't be 
a problem.

The only release that was doing it differently was one release of Fedora 
Core (don't remember if it was 1 or 2).  That one would create RAID1 and 
force it not to resync.  Assumption was that for ext3 and swap 
partitions it doesn't hurt if unused blocks were different on each 
submirror.  Which is true as long as your file systems are clean.  They 
chagned back to the old behaviour at one point down the road.

-- 
Aleksandar Milivojevic <amilivojevic at pbl.ca>    Pollard Banknote Limited
Systems Administrator                           1499 Buffalo Place
Tel: (204) 474-2323 ext 276                     Winnipeg, MB  R3T 1L7