[Lustre-discuss] possible file corruption

[Faccini, Bruno]

Hello Jason,

Only case I know of such scenario you describe (ie, with no eviction msg at all) is what I reported from CEA site as part of LU-1974. But as you can see/read there, it was after some incomplete patch integration process which finally introduced a regression in Lustre-Client causing dirty-pages to not be flushed to Servers/OSTs when reaching their granted space and needed to renew it !!

May be you can run with "echo +cache > /proc/sys/lnet/[debug,printk]" traces enabled just to identify if you encounter the same kind of issue …
Bruno. 

Le Dec 4, 2012 à 3:52 PM, Jason Temple <jtemple at cscs.ch>
 a écrit :

> Hello,
> 
> I have a troubling issue with random file corruption using either lustre
> 1.8.6 (internal Cray lustre) and lustre 2.1 (sonexion - produced by
> xyratex).
> 
> Randomly, our users will come across an issue with files either having 0
> size, or being corrupted.  The 0 size files are usually ascii files
> (which are normally created with simple cat and awk statements,
> serially), while the corrupted files are weather data (grib) files that
> most of the time are truncated during an untar operation. Other times,
> the files have blocks filled with zeroes in the middle of the file.
> 
> The real kicker is that we can not reproduce the problem reliably in
> order to troubleshoot it.  I managed to trigger file truncation after
> 1500 iterations of untaring the same tar file, but since then, after
> 30,000 iterations, I haven't been able to reproduce it.
> 
> When it happens, there are no errors in the logs relating to lustre, and
> nothing is dumped into /tmp.
> 
> Has anyone come across this before?  I've searched google for weeks, but
> have only found a few bugs that seem like they might be similar, but are
> usually related to netcdf and parallel i/o, while our cases of
> corruption are usually encountered serially.
> 
> What log settings are suggested to try and capture this phantom while it
> is happening?
> 
> Thanks in advance,
> 
> Jason
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