Re: subsystem_debug and mem_used in proc

These are client nodes and in fact, this class of node is running a 
particular application that intermittently fails leaving a lustre 
error in syslog.

"mg38 kernel: LustreError: 
10147:0:(lov_request.c:180:lov_update_enqueue_set()) error: enqueue 
objid 0x3922667 subobj 0x15dfc on OST idx 1: rc = -4"

While mg38 is currently showing a negative valued for memused, I have 
not been able to tie that to a failure.  The error message points to 
the same file

Jan

At 1:34 PM -0600 4/4/07, Andreas Dilger wrote:
> On Apr 04, 2007  11:28 -0800, Jan H. Julian wrote:
> >  Could someone please clarify the use of the proc values for
> >  subsystem_debug and memused.  In regard to
> >  /proc/sys/portals/subsystem_debug and /proc/sys/portals/debug, should
> >  both be set to zero to totally turn of debugging?
> >
> >  In regard to /proc/sys/lustre/memused we see quite a variety of
> >  entries included many with negative values.  Does the negative value
> >  have a particular meaning?
> >  For instance "cat /proc/sys/lustre/memused" for 9 nodes shows:
> >  ...
> >  mg07  102186899
> >  mg08  101775995
> >  mg09  -1323553489
> >  mg10  -1328553965
> >  mg11  -1378379739
> >  mg12  -1347059989
> >  mg13  -1364717487
> >  mg14  -1358477913
> >  mg15  24680370
> >
> >  These are 16 core  machines with 64GB of resident memory.
>
> This appears to be an overflow of a 32-bit counter.  It isn't strictly
> harmful, because it will underflow an equal amount later on and should
> return to zero when Lustre unmounts.  It does make this stat less useful
> on machines with lots of RAM.
>
> Are these client or server nodes?  I'm a bit surprised that Lustre would
> be allocating > 2GB of RAM.
>
> Cheers, Andreas
> --
> Andreas Dilger
> Principal Software Engineer
> Cluster File Systems, Inc.


--
Jan Julian     University of Alaska, ARSC    
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