Re: Data recovery from a RAID set with XP Pro


"TDA171" <TDA171@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:7BD04B1B-1C0A-4C1F-9C7F-8EE42568BFF9@xxxxxxxxxxxxxxxx
> Thanks Walter:
> I fear I am not certain which is Mirror and which is Stripe. As the four
> drives are set up as two pairs of Master and Slave, is it safe to assume
> that
> one Master and the paired Slave are doing the same job ie mirror or
> stripe,
> and can I isolate each pair in turn to try and establish which if any of
> the
> drives has gone down??

Unfortunately making assumptions in this instance is not a good thing. A
RAID 0+1 can be configured so that a channel mirrors a channel with the
stripe being master/slave or the stripe could run across channels with the
slaves being the mirrors. All of that is determined when the RAID is
defined. You should be able to get into the RAID BIOS, assuming it's not a
controller, to see what the configuration is. If not, try pulling just one
drive at a time.

>
> Second question: If I reinstalled OS, would I loose the data if I
> reestablished the RAID? For some time I was receiving message 'incomplete
> raid' yet the server still delivered all data on request.....until it
> refused
> to boot just recently.

Uh-oh. You've been getting RAID failure messages for a while that you've
been ignoring?

Very much definitely a very big bad no-no, especially when dealing with
stripes. Depending on the failure mode, you may very well be looking at
total data loss. From the sound of it the source/mirror got out of synch,
most likely due to hardware failure and the remaining functional stripe has
now crapped out. Unless the issue is with the controller rather than the
drive, it's not looking good.

Never, ever ignore error messages when it comes to a RAID. Always address
any error message immediately.

If you can't get things up by simply replacing a single drive, or at most a
pair of drives assuming that's a stripe pair and you don't know what the
RAID geometry is then you're probably definitely looking at total data loss.

>
> Any help would be appreciated
>
> Tim

--
Walter Clayton
Any technology distinguishable from magic is insufficiently advanced.
http://www.dts-l.org


.

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