Disc failure on a software RAID system has killed everything

[Gary Stainburn]

On Wednesday 19 May 2010 12:13:12 Bryn M. Reeves wrote:
> On 05/19/2010 12:04 PM, Gary Stainburn wrote:
> > Hi folks,
> >
> > I've got a PC with 5x500GB HDD's running software raid.  On drive 0 and 1
> > I had RAID0 for the boot partition and then on all 5 drives I had RAID 5
> > for everything else.
>
> Why use RAID0 for the boot partition? That means that a failure of
> either drive will make the system unbootable (since half the file system
> needed for booting is on the dead device).
>
> I tend to use RAID1 for boot devices, RAID5 for general storage (where I
> either don't care too much about write performance or expect a low level
> of write I/O). I would only use RAID0 for transient data that can be
> easily regenerated after a hardware failure (or combine it with RAID1 if
> you need to combine redundancy with better write performance but make
> sure you understand the way that different stackings behave[1]).

Sorry Bryn, I mean RAID1.

I thought that with RAID1, if I disconnected the dead one it should either 
just work, or i should be able to access both that and the RAID5 setup from 
the bood DVD.

However, as I said, it won't boot and the rescue DVD doesn't see the Linux 
partitions, presumably because it can't/won't use the RAID devices


-- 
Gary Stainburn
 
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