Problems with kernel 3.6.x (vm ?) (was : Is kernel 3.6.1 or filestreams option toxic ?)

[Yann Dupont]

Le 29/10/2012 00:48, Dave Chinner a écrit :
>
> This is reproductible. Here is how to do it :
>
> - Started a 3.6.2 kernel.
>
> - I created a fresh lvm volume on localdisk of 20 GB.
> Can you reproduce the problem without LVM?

Hello dave. That is THE question. My intent was to test with and without 
LVM. But right now I can't , because all my disks are consumed by lvm.
In fact my test setup hasn't even enough space to locally clone the 
volume where I have errors. I only have 146 sas disks on this machine.

I have to setup another test platform, and as I'm currently traveling, 
it won't be easy before  next week.

What I want to try this week is to recrash a volume, possibly smaller,
download this image on another machine with kvm
see if I have the mounting problems inside this kvm
begin to bisect the kernel .

...
>
> - After some try, I finally had the impossibility to mount the xfs
> volume, with the error reported in previous mails. So far this is
> normal .
> So it doesn't happen every time, and it may be power cycle related.

Yes, during my tests, I had to to power cycle 3 or 4 times before having 
the actual problem

> What is your "local disk"?

Raid 1 array (2 disks) with mptsas on this.
>
>> xfs_logprint don't say much :
>>
>> xfs_logprint:
>>      data device: 0xfe02
>>      log device: 0xfe02 daddr: 10485792 length: 20480
>>
>> Header 0x7c wanted 0xfeedbabe
>> **********************************************************************
>> * ERROR: header cycle=124         block=5414 *
>> **********************************************************************
> You didn't look past the initial error, did you? The file is only
> 482280 lines long, and 482200 lines of that are decoded log data....
> :)
Well I'd tried with -c  but sorry, i didn't had experience with 
xfs_logprint so far.
>
>> I tried xfs_logprint -c , it gaves a 22M file. You can grab it here :
>> http://filex.univ-nantes.fr/get?k=QnBXivz2J3LmzJ18uBV
> I really need the raw log data, not the parsed output. The logprint
> command to do that is "-C <file>", not "-c".

Ok ... I should have read the man page more carefully. Time to restart a 
crash session

>> - Rebooted 3.4.15
>> - xfs_logprint gives the exact same result that with 3.6.2 (diff
>> tells no differences)
> Given that it's generated by the logprint application, I'd expect it
> to be identical.
Me too, but I'd also expect the log replaying to be identical between 
the 2 kernels

>
>> but on 3.4.15, I can mount the volume without problem, log is
>> replayed.
>> for information here is xfs_info of the volume :
>>
>> here is xfs_info output
>>
>> root at label5:/mnt/debug# xfs_info /mnt/tempo
>> meta-data=/dev/mapper/LocalDisk-crashdisk isize=256    agcount=8,
>> agsize=655360 blks
> How did you get a default of 8 AGs? That seems wrong.  What version
> of mkfs.xfs are you using?
root at label5:~# mkfs.xfs -V
mkfs.xfs version 3.1.7

the volume was freshly formatted, with defaults options. Absolutely 
nothing special on my side.
Cheers,

-- 
Yann Dupont - Service IRTS, DSI Université de Nantes
Tel : 02.53.48.49.20 - Mail/Jabber : Yann.Dupont at univ-nantes.fr