[Pvfs2-users] Data corruption?

[Rob Ross]

The problem with storing things like parent directory handle in a given 
directory/metafile is that you have to change them all in the event of a 
rename. Gets nasty.

Rob

Murali Vilayannur wrote:
> Hi Simon,
> 
>> The kernel where these errors are reported is 2.6.16-1.2115_FC4smp and
>> the files were restored using
>> rsync -avv -B 4194304 /media/pvfs_backup/pvfs2-fs/   /pvfs2-fs/
>>
>> The "-B" forces a reasonable (4MB) block size, and it's
>> rsync-2.6.8-1.FC4.1 which just uses read/write VFS calls.
> 
> Hmm.. I will also try and see if we can reproduce this error on our
> setup..
> 
>> Is there any way of find which file/directory corresponds to a given handle?
> 
> For a given handle, we can find out if it is a file or a directory.
> But to know what is the name of the file/directory may not be possible
> right now without traversing the entire tree and checking for the given
> handle.
> We could possibly store the parent handle as part of the keyval for the
> given handle and work our way backwards. Sam and I had discussed the
> possibility of doing that for some other thing. Just not sure if that was
> worth the effort or if it was useful for any other feature.
> But it sure seems like having that would be a good diagnostic aid in case
> something bad happens..
> Thanks,
> Murali
> 
>>
>> Sam Lang wrote:
>>
>>> Hi Simon,
>>>
>>> I'm not able to reproduce this yet on my machine.  Can you give me more
>>> details about your setup?  What kernel version are you running on?  When
>>> you did the restore from XFS, did you just copy everything over using cp?
>>>
>>> -sam
>>>
>>> Number Cruncher wrote:
>>>
>>>
>>>> Sam Lang wrote:
>>>>
>>>>
>>>>
>>>>>> [E 13:38:09.445405] TROVE:DBPF:Berkeley DB: DB->get: DB_NOTFOUND: No
>>>>>> matching key/data pair found
>>>>>> [E 13:38:09.448542] TROVE:DBPF:Berkeley DB: DB->get: DB_NOTFOUND: No
>>>>>> matching key/data pair found
>>>>>> [E 13:38:09.470425] TROVE:DBPF:Berkeley DB: DB->get: DB_NOTFOUND: No
>>>>>> matching key/data pair found
>>>>>>
>>>>>>
>>>>>>
>>>>> This message was being printed for a non-failure case.  Its been removed
>>>>> for that case in the 1.5.1 release.  It doesn't mean that anything is
>>>>> wrong with your filesystem.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> The client kernel also sometimes reports:
>>>>>>
>>>>>> pvfs2_file_read: error writing to handle 1840698453, -- returning -2
>>>>>>
>>>>>>
>>>>>>
>>>>> I'm not sure about this one.  Is it always the same handle?
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>> Yes, I think so.
>>>>
>>>>
>>>>
>>>>>> And pvfs2-fsck gives:
>>>>>> ....
>>>>>> # looking for dirdata match to 920349294.
>>>>>> # mgmt_get_dirdata returned 920349293.
>>>>>> # looking for dirdata match to 613565917.
>>>>>> # mgmt_get_dirdata returned 613565916.
>>>>>> # looking for dirdata match to 1227132674.
>>>>>> # mgmt_get_dirdata returned 1227132673.
>>>>>> # second pass: finding orphaned sub trees.
>>>>>> * not removing None 2454203121.
>>>>>>
>>>>>>
>>>>>>
>>>>> The lines beginning with # are ok, this one is a little odd.  Could you
>>>>> send the whole output from fsck?
>>>>>
>>>>>
>>>>>
>>>>>
>>>> It's a bit long (50k lines), so I've attached it as .txt.bz2
>>>>
>>>>
>>>>
>>>>
>>>>
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