RAID 10 recovery question

I'm hoping someone will see this and set my mind at ease.

I have a Dell PE 2600 with 6 73GB 15k SCSI drives on a PERC 4/Di
controller arranged as follows:

Physical Disks:
Disks 0 & 1 = RAID 1 (OS partition, Server2003)
Disks 2 & 3 = RAID 0 (Array 1)
Disks 4 & 5 = RAID 0 (Array 2)

Logical Drives:
0 = OS partition
1 = RAID 1 (Array1 & Array 2)

Here's what happened and the issue I am having:

When moving the server from one rack to another the BIOS lost its
settings, evidently the battery was dead.

The BIOS showed the Integrated controller in SCSI mode instead of RAID
mode.

To ensure I didn't lose any of the data on physical disks 2 - 5, I
numbered and removed them from the server.

Then I replaced the battery and checked to make sure the BIOS was
holding the settings even in a no-power situation. After I confirmed
that I changed the mode to RAID and the machine restarted.

When I booted into the RAID configuration, disk 1 showed as "FAILED",
so I rebuilt it and then rebooted.

This time the machine booted into Server 2003 without a hitch, so I
shut it down and then re-inserted disks 2 - 5 and powered the machine
back on. Server 2003 started with no problems but could not see the
logical drive 1.

I rebooted into the RAID configuration. Disks 2 & 3 show "FAILED" and
disks 4 & 5 show "ONLINE". The RAID controller will not allow me to
rebuild disks 2 or 3.

If my understanding is correct, disks 4 & 5 should be a striped set
that contain all information of the mirrored set of disks 2 & 3. In
theory at least, this should be a recoverable state, but I don't want
to monkey around and end up losing the data on logical drive 1 since
it contains newly installed software that (as you may have guessed)
has not been backed up yet.

Any ideas, thoughts, or resources that you may offer will be greatly
appreciated.

"RAIDwoes" <> wrote in message
news: ps.com...
> I'm hoping someone will see this and set my mind at ease.
>
> I have a Dell PE 2600 with 6 73GB 15k SCSI drives on a PERC 4/Di
> controller arranged as follows:
>
> Physical Disks:
> Disks 0 & 1 = RAID 1 (OS partition, Server2003)
> Disks 2 & 3 = RAID 0 (Array 1)
> Disks 4 & 5 = RAID 0 (Array 2)
>
> Logical Drives:
> 0 = OS partition
> 1 = RAID 1 (Array1 & Array 2)
>
> Here's what happened and the issue I am having:
>
> When moving the server from one rack to another the BIOS lost its
> settings, evidently the battery was dead.
>
> The BIOS showed the Integrated controller in SCSI mode instead of RAID
> mode.
>
> To ensure I didn't lose any of the data on physical disks 2 - 5, I
> numbered and removed them from the server.
>
> Then I replaced the battery and checked to make sure the BIOS was
> holding the settings even in a no-power situation. After I confirmed
> that I changed the mode to RAID and the machine restarted.
>
> When I booted into the RAID configuration, disk 1 showed as "FAILED",
> so I rebuilt it and then rebooted.
>
> This time the machine booted into Server 2003 without a hitch, so I
> shut it down and then re-inserted disks 2 - 5 and powered the machine
> back on. Server 2003 started with no problems but could not see the
> logical drive 1.
>
> I rebooted into the RAID configuration. Disks 2 & 3 show "FAILED" and
> disks 4 & 5 show "ONLINE". The RAID controller will not allow me to
> rebuild disks 2 or 3.
>
> If my understanding is correct, disks 4 & 5 should be a striped set
> that contain all information of the mirrored set of disks 2 & 3. In
> theory at least, this should be a recoverable state, but I don't want
> to monkey around and end up losing the data on logical drive 1 since
> it contains newly installed software that (as you may have guessed)
> has not been backed up yet.
>
> Any ideas, thoughts, or resources that you may offer will be greatly
> appreciated.
>

Cut and paste your post here and I bet you'll receive more responses with
more first-hand knowledge:

http://www.dellcommunity.com/support...d=pes_hardrive

You may have to register, but it will be worth it.

Good luck -

Stew

Stew

"RAIDwoes" <> wrote in message
news: ps.com...
> I'm hoping someone will see this and set my mind at ease.
>
> I have a Dell PE 2600 with 6 73GB 15k SCSI drives on a PERC 4/Di
> controller arranged as follows:
>
> Physical Disks:
> Disks 0 & 1 = RAID 1 (OS partition, Server2003)
> Disks 2 & 3 = RAID 0 (Array 1)
> Disks 4 & 5 = RAID 0 (Array 2)
>
> Logical Drives:
> 0 = OS partition
> 1 = RAID 1 (Array1 & Array 2)
>
> Here's what happened and the issue I am having:
>
> When moving the server from one rack to another the BIOS lost its
> settings, evidently the battery was dead.
>
> The BIOS showed the Integrated controller in SCSI mode instead of RAID
> mode.
>
> To ensure I didn't lose any of the data on physical disks 2 - 5, I
> numbered and removed them from the server.
>
> Then I replaced the battery and checked to make sure the BIOS was
> holding the settings even in a no-power situation. After I confirmed
> that I changed the mode to RAID and the machine restarted.
>
> When I booted into the RAID configuration, disk 1 showed as "FAILED",
> so I rebuilt it and then rebooted.
>
> This time the machine booted into Server 2003 without a hitch, so I
> shut it down and then re-inserted disks 2 - 5 and powered the machine
> back on. Server 2003 started with no problems but could not see the
> logical drive 1.
>
> I rebooted into the RAID configuration. Disks 2 & 3 show "FAILED" and
> disks 4 & 5 show "ONLINE". The RAID controller will not allow me to
> rebuild disks 2 or 3.
>
> If my understanding is correct, disks 4 & 5 should be a striped set
> that contain all information of the mirrored set of disks 2 & 3. In
> theory at least, this should be a recoverable state, but I don't want
> to monkey around and end up losing the data on logical drive 1 since
> it contains newly installed software that (as you may have guessed)
> has not been backed up yet.
>
> Any ideas, thoughts, or resources that you may offer will be greatly
> appreciated.
>

Not really a help suggestion but why RAID 10 ? why not RAID 1 on disks 0+1
and then RAID 5 on disks 2+3+4 and then have disk 6 as a hot spare? giving
the same amount of disk space as in your RAID 10 but then still having a hot
spare to cover redundancy on either your O/S RAID or your Apps RAID?



By the way have you tried swapping disks 2+3 they are in the right slots?

On Tue, 12 Jun 2007 08:59:47 GMT, "Fixer" <>
wrote:

>Not really a help suggestion but why RAID 10 ? why not RAID 1 on disks 0+1
>and then RAID 5 on disks 2+3+4 and then have disk 6 as a hot spare? giving
>the same amount of disk space as in your RAID 10 but then still having a hot
>spare to cover redundancy on either your O/S RAID or your Apps RAID?

Due to the writes on RAID5 being slower than RAID10 - this is the
exact configuration I use for database servers at work, and the email
servers run like this also, as I have seen the email server run on
RAID5 and being noticeably slower than on RAID10.

Why the disks were marked as failed I don't know - the information
about the RAIDs should be actually written to the disks themselves,
but the OP is correct - if he has a RAID10 system, this consists of
two spanned RAID0 drives, so if the two disks fail, he is left with a
RAID0 set. In RAID5, if these two disks failed, and they both weren't
the hotspare, he would have lost the data.

Andrew.