Re: raid 1

[Mike Bird <mgb-debian@yosemite.net>]

On Wednesday 18 July 2007 15:50, besonen wrote:
> is it true that with software raid 1 that i cannot have the boot drive
> protected?

No.  However, getting the mirror of the boot drive to be bootable
under grub in readiness for when the boot drive fails does not seem
to me to be quite as easy/reliable as it was under LILO.  Maybe a
grub expert can post a reliable recipe here.

> if this is the case what are some work-arounds besides using a 
> 3ware controller for just the boot drive?

n/a

> can i take a single drive that was part of a mirrored array and attach it
> to another computer and access the data?

With software RAID 1 yes.  (But not with other RAID levels.)

> if a hard drive in a mirrored array fails, and i replace the failed drive,
> will the array auto-rebuild?

Software RAID usually mirrors partitions rather than whole drives.

You'll need to partition the new drive and add the new partititions to
the RAIDs.  A couple of minutes work.  The mirrors will then rebuild.

> and during the rebuild process, can the 
> rebuild be throttled such that the system remains usable while the rebuild
> occurs?

Yes.  You can change the speedlimits by echoing integers into
/proc/sys/dev/raid/speed_limit_{min,max}

--Mike Bird