[Linux-cluster] unformat gfs2

[Digimer]

That is very good news! Now, about your backups... ;)

Look forward to seeing your code!

digimer

On 22/03/14 04:13 PM, Mr.Pine wrote:
> Good news for all :
> I successfully recoved all of my data(1.5TB) without even one bit lost!
> my program tooks only 1 hour to do all the jobs on my 1.7 TB
> partition.(I could not wait 100 days for my bash script to finish).
>
> I will publish my  source code very soon for the public use.
>
> Special thanks to Bob for the help.
>
> Mr.Pine
>
> On Wed, Mar 19, 2014 at 4:58 PM, Bob Peterson <rpeterso at redhat.com> wrote:
>> ----- Original Message -----
>>> Hi,
>>>
>>> Scripts is very very slow, so i should write program in c/c++.
>>>
>>> I need some confidence about data structures and data location on disk.
>>> As i reviewed blocks of data:
>>>
>>> All reserved blocks (GFS2 specific blocks) start by : 0x01161970
>>> Blocktype store location is at Byte # 8,
>>> Type of start block of each resource group is: 2
>>> Bitmaps are in block types 2 & 3.
>>> In block type 2, bitmap info starts from Byte # 129
>>> In block type 3, bitmap info starts from Byte # 25
>>> Length of RGs are const, 5 in my volume (out put of gfs2_edit -p rindex
>>> /dev/..)
>>>
>>> Is this info right?
>>>
>>> Logic of my program seams should be like this:
>>>
>>> (1)
>>> Loop in device and temporary store block id of dinode blocks, and also
>>> their bitmap locations
>>>
>>> (2)
>>> Change bitmap of blocks to 3 (11)
>>>
>>> Bob, could you confirm this?
>>>
>>> Regards
>>> Pine.
>>
>> Hi Pine,
>>
>> This is correct. The length of RGs is properly determined by the values
>> in the "rindex" system file, but 5 is very common, and is usually constant.
>> (It may change if you used gfs2_grow or gfs2_convert from gfs1).
>> The bitmap is 2 bits per block in the resource group, and it's relative
>> to the start of the particular rgrp. You should probably use the same
>> algorithm in libgfs2 to change the proper bit in the bitmaps. You can
>> get this from the public gfs2-utils git tree.
>>
>> Regards,
>>
>> Bob Peterson
>> Red Hat File Systems
>>
>> --
>> Linux-cluster mailing list
>> Linux-cluster at redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-cluster
>


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