Re: Help with data recovering

[Maxim Mikheev <mikhmv@gmail.com>]

Option -i was helpful.
Some date was restored.

during restoring some files I got message "ret is -3". This files has 0 
size.
Can anyone tell me what is code "-3" mean. Is it recoverable?

So basically data is on harddrives but not completely available.
the questions is: Is it possible to btrfs push to roll back on several 
generations?

Thanks

On 06/04/2012 02:37 PM, Michael wrote:
> Below is what you used? So you have RAID 0 for data, RAID 1 for
> metadata. This doesn't help any, but a point of info.
> # Create a filesystem across four drives (metadata mirrored, data striped)
> mkfs.btrfs /dev/sdb /dev/sdc /dev/sdd /dev/sde
>
>
> Just to make sure I understand correctly: This FS with critical info
> used a non-production filesystem, in RAID 0(no redundancy), with no
> backups.
>
> Another option I found(and I am no authority on the subject) is to use
> btrfs.restore with -i
> -i: Ignore errors. Normally the restore tool exits immediately for any
> error. This option forces it to keep going if it can, usually this
> results in some missing data.
> Again, this can be destructive, and it would be very smart to make
> block level copies of everything.
>
> On Mon, Jun 4, 2012 at 1:03 PM, Maxim Mikheev<mikhmv@gmail.com>  wrote:
>> It was a RAID0 unfortunately.
>>
>>
>> On 06/04/2012 02:02 PM, Michael wrote:
>>> If he has it in a RAID 1, could he manually fail the bad disk and try
>>> it from there? Obviously this could be harmful, so a dd copy would be
>>> a VERY good idea(truthfully, that should have been the first thing
>>> that was done).
>>> Michael
>>>
>>> On Mon, Jun 4, 2012 at 12:09 PM, Hugo Mills<hugo@carfax.org.uk>    wrote:
>>>> On Mon, Jun 04, 2012 at 06:04:22PM +0100, Hugo Mills wrote:
>>>>>     I'm out of ideas.
>>>>    ... but that's not to say that someone else may have some ideas. I
>>>> wouldn't get your hopes up too much, though.
>>>>
>>>>>     At this point, though, you're probably looking at somebody writing
>>>>> custom code to scan the FS and attempt to find and retrieve anything
>>>>> that's recoverable.
>>>>>
>>>>>     You might try writing a tool to scan all the disks for useful
>>>>> fragments of old trees, and see if you can find some of the tree roots
>>>>> independently of the tree of tree roots (which clearly isn't
>>>>> particularly functional right now). You might try simply scanning the
>>>>> disks looking for your lost data, and try to reconstruct as much of it
>>>>> as you can from that. You could try to find a company specialising in
>>>>> data recovery and pay them to try to get your data back. Or you might
>>>>> just have to accept that the data's gone and work on reconstructing
>>>>> it.
>>>>    Hugo.
>>>>
>>>> --
>>>> === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
>>>>   PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
>>>>   --- A linked list is still a binary tree.  Just a very unbalanced ---
>>>>                              one.  -- dragon