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Jeff Sadino 03-04-2010 02:24 AM

Recover RAID
 
Ok, I'm learning a lot about raids and what to do, and what not to do.* Looking at some info I had before, md1 was 200GB in size, which makes sense, but it was only 39GB full.* The way I repartitioned drive 1, I probably overwrote only about 11GB.* Does that make it any easier to recover any amount of the raid?* Is there some sort of "recover lost partitions" option in Linux or gparted?



Thank you!
Jeff

On Wed, Mar 3, 2010 at 4:55 PM, Les Mikesell <lesmikesell@gmail.com> wrote:


Jeff Sadino wrote:

> Thanks for the insight. *Is there any way to bring it back to life not

> necessarily as a raid, but just back up so I can get to the data and

> have my license managers working? *What if I edit md1 out of the raidtab

> file?

>



The data on a raid0 stripes across both drives as though it were one big

cylinder. *You aren't going to make md1 work work with one missing. *You should

be able to recover what was on md0 (a raid1) from either of its members.



--

* Les Mikesell

* *lesmikesell@gmail.com

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"nate" 03-04-2010 02:33 AM

Recover RAID
 
Jeff Sadino wrote:
> Ok, I'm learning a lot about raids and what to do, and what not to do.
> Looking at some info I had before, md1 was 200GB in size, which makes sense,
> but it was only 39GB full. The way I repartitioned drive 1, I probably
> overwrote only about 11GB. Does that make it any easier to recover any
> amount of the raid? Is there some sort of "recover lost partitions" option
> in Linux or gparted?

The partition is just a map, if you can re-create the partition
exactly the way it was before, the data should still be there if
it wasn't overwritten.

But as far as I know there isn't a backup stored of the partition
table, if the disk is exactly the same as the other member, then you
can try duplicating the partition setup using the first disk as
a guide.

I don't know whether or not it will help restore a RAID 0 set,
but may be worth a shot since the situation probably can't get
much worse.

nate


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Christopher Chan 03-04-2010 02:40 AM

Recover RAID
 
On Thursday, March 04, 2010 11:33 AM, nate wrote:
> Jeff Sadino wrote:
>> Ok, I'm learning a lot about raids and what to do, and what not to do.
>> Looking at some info I had before, md1 was 200GB in size, which makes sense,
>> but it was only 39GB full. The way I repartitioned drive 1, I probably
>> overwrote only about 11GB. Does that make it any easier to recover any
>> amount of the raid? Is there some sort of "recover lost partitions" option
>> in Linux or gparted?
>
> The partition is just a map, if you can re-create the partition
> exactly the way it was before, the data should still be there if
> it wasn't overwritten.

That problem was that he had it formatted as ext3...


>
> But as far as I know there isn't a backup stored of the partition
> table, if the disk is exactly the same as the other member, then you
> can try duplicating the partition setup using the first disk as
> a guide.

+1


>
> I don't know whether or not it will help restore a RAID 0 set,
> but may be worth a shot since the situation probably can't get
> much worse.


Just hope that the ext3 format only hit blocks contain non-essential
data...and nothing related to filesystem structure and yada, yada
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Ross Walker 03-04-2010 03:40 AM

Recover RAID
 
On Mar 3, 2010, at 10:24 PM, Jeff Sadino <jsadino.queens@gmail.com>
wrote:

> Ok, I'm learning a lot about raids and what to do, and what not to
> do. Looking at some info I had before, md1 was 200GB in size, which
> makes sense, but it was only 39GB full. The way I repartitioned
> drive 1, I probably overwrote only about 11GB. Does that make it
> any easier to recover any amount of the raid? Is there some sort of
> "recover lost partitions" option in Linux or gparted?

Don't you have backups of this data?

You can just re-create the raid0 and restore the data.

-Ross

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Jeff Sadino 03-04-2010 04:15 AM

Recover RAID
 
Backups?* I wish :)* I will now.
But looking closer, that md1 is not my OS partition, just a data partition.* If I take that md1 entry out of the raidtab file and restart the computer, I would think that it would start up just fine, minus the data partition (and for the moment neglecting any vital programs that might be installed on that partition).* My question is when I start the computer back up, in order to start up without that partition there any more, will the OS write any new files or anything that will not be reversible?




Thank you again,
Jeff

On Wed, Mar 3, 2010 at 6:40 PM, Ross Walker <rswwalker@gmail.com> wrote:



On Mar 3, 2010, at 10:24 PM, Jeff Sadino <jsadino.queens@gmail.com>

wrote:



> Ok, I'm learning a lot about raids and what to do, and what not to

> do. *Looking at some info I had before, md1 was 200GB in size, which

> makes sense, but it was only 39GB full. *The way I repartitioned

> drive 1, I probably overwrote only about 11GB. *Does that make it

> any easier to recover any amount of the raid? *Is there some sort of

> "recover lost partitions" option in Linux or gparted?



Don't you have backups of this data?



You can just re-create the raid0 and restore the data.



-Ross



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Christopher Chan 03-04-2010 04:34 AM

Recover RAID
 
On Thursday, March 04, 2010 01:15 PM, Jeff Sadino wrote:
> Backups? I wish :) I will now.

/me hands Jeff a big clueby4 to use on the former admin.


> But looking closer, that md1 is not my OS partition, just a data
> partition. If I take that md1 entry out of the raidtab file and restart
> the computer, I would think that it would start up just fine, minus the
> data partition (and for the moment neglecting any vital programs that
> might be installed on that partition). My question is when I start the
> computer back up, in order to start up without that partition there any
> more, will the OS write any new files or anything that will not be
> reversible?

Yes...logs mainly. Most probably not reversible that lot. You may need
to comment out the entry in /etc/fstab for md1 too. You might see
messages from services tied to the data partition and if they get in the
way of start up, just go into single-user mode and disable them...


>
> Thank you again,
> Jeff
>
> On Wed, Mar 3, 2010 at 6:40 PM, Ross Walker <rswwalker@gmail.com
> <mailto:rswwalker@gmail.com>> wrote:
>
> On Mar 3, 2010, at 10:24 PM, Jeff Sadino <jsadino.queens@gmail.com
> <mailto:jsadino.queens@gmail.com>>
> wrote:
>
> > Ok, I'm learning a lot about raids and what to do, and what not to
> > do. Looking at some info I had before, md1 was 200GB in size, which
> > makes sense, but it was only 39GB full. The way I repartitioned
> > drive 1, I probably overwrote only about 11GB. Does that make it
> > any easier to recover any amount of the raid? Is there some sort of
> > "recover lost partitions" option in Linux or gparted?
>
> Don't you have backups of this data?
>
> You can just re-create the raid0 and restore the data.
>
> -Ross
>
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>
>
>
>
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Les Mikesell 03-04-2010 04:39 AM

Recover RAID
 
Jeff Sadino wrote:
> Backups? I wish :) I will now.
> But looking closer, that md1 is not my OS partition, just a data
> partition. If I take that md1 entry out of the raidtab file and restart
> the computer, I would think that it would start up just fine, minus the
> data partition (and for the moment neglecting any vital programs that
> might be installed on that partition). My question is when I start the
> computer back up, in order to start up without that partition there any
> more, will the OS write any new files or anything that will not be
> reversible?

You'll need to take the mount point out of /etc/fstab to come up without it. I
don't think it even matters that the raid assembly fails but not being able to
mount everything in fstab is fatal.

--
Les Mikesell
lesmikesell@gmail.com

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"Sorin Srbu" 03-04-2010 06:12 AM

Recover RAID
 
From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf
Of Jeff Sadino
Sent: Thursday, March 04, 2010 6:15 AM
To: CentOS mailing list
Subject: Re: [CentOS] Recover RAID

Backups?* I wish :)* I will now.
But looking closer, that md1 is not my OS partition, just a data partition.*
If I take that md1 entry out of the raidtab file and restart the computer, I
would think that it would start up just fine, minus the data partition (and
for the moment neglecting any vital programs that might be installed on that
partition).* My question is when I start the computer back up, in order to
start up without that partition there any more, will the OS write any new
files or anything that will not be reversible?
----

Eh? Raid0 with no backups? For real?

--
/Sorin
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Timo Schoeler 03-04-2010 06:15 AM

Recover RAID
 
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

thus Sorin Srbu spake:
> From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf
> Of Jeff Sadino
> Sent: Thursday, March 04, 2010 6:15 AM
> To: CentOS mailing list
> Subject: Re: [CentOS] Recover RAID
>
> Backups? I wish :) I will now.
> But looking closer, that md1 is not my OS partition, just a data partition.
> If I take that md1 entry out of the raidtab file and restart the computer, I
> would think that it would start up just fine, minus the data partition (and
> for the moment neglecting any vital programs that might be installed on that
> partition). My question is when I start the computer back up, in order to
> start up without that partition there any more, will the OS write any new
> files or anything that will not be reversible?
> ----
>
> Eh? Raid0 with no backups? For real?

Backups are for sissies; running a hara-kiri RAID demands *not* having
backups. Or did the kamikaze pilots have parachutes?

SCNR
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Version: GnuPG v1.4.5 (GNU/Linux)

iD8DBQFLj14Efg746kcGBOwRAuicAJ4uNeMpsbc9N0dSbOUe0J Fkh4hXrgCeJtbb
b/cpUWfQxgfxTjLPo7TWwsQ=
=t8zn
-----END PGP SIGNATURE-----
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Jeff Sadino 03-04-2010 06:17 AM

Recover RAID
 
Thanks Timo, that one actually made me laugh!

On Wed, Mar 3, 2010 at 9:15 PM, Timo Schoeler <timo.schoeler@riscworks.net> wrote:


-----BEGIN PGP SIGNED MESSAGE-----

Hash: SHA1



thus Sorin Srbu spake:

> From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf

> Of Jeff Sadino

> Sent: Thursday, March 04, 2010 6:15 AM

> To: CentOS mailing list

> Subject: Re: [CentOS] Recover RAID

>

> Backups? *I wish :) *I will now.

> But looking closer, that md1 is not my OS partition, just a data partition.

> If I take that md1 entry out of the raidtab file and restart the computer, I

> would think that it would start up just fine, minus the data partition (and

> for the moment neglecting any vital programs that might be installed on that

> partition). *My question is when I start the computer back up, in order to

> start up without that partition there any more, will the OS write any new

> files or anything that will not be reversible?

> ----

>

> Eh? Raid0 with no backups? For real?



Backups are for sissies; running a hara-kiri RAID demands *not* having

backups. Or did the kamikaze pilots have parachutes?



SCNR

-----BEGIN PGP SIGNATURE-----

Version: GnuPG v1.4.5 (GNU/Linux)



iD8DBQFLj14Efg746kcGBOwRAuicAJ4uNeMpsbc9N0dSbOUe0J Fkh4hXrgCeJtbb

b/cpUWfQxgfxTjLPo7TWwsQ=

=t8zn

-----END PGP SIGNATURE-----

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