[lustre-discuss] MDS crashing: unable to handle kernel paging request at 00000000deadbeef (iam_container_init+0x18/0x70)

[Mark Hahn]

>> Our problem seems to correlate with an unintentional creation of a tree of >500M files.  Some of the crashes we've had since then appeared
>> to be related to vm.zone_reclaim_mode=1.  We also enabled quotas right after the 500M file thing, and were thinking that inconsistent
>> quota records might cause this sort of crash.
>
> Have you set vm.zone_reclaim_mode=0 yet?  I had an issue with this on my
> file system a while back when it was set to 1.

all our existing Lustre MDSes run happily with vm.zone_reclaim_mode=0,
and making this one consistent appears to have resolved a problem
(in which one family of lustre kernel threads would appear to spin,
"perf top" showing nearly all time spent in spinlock_irq.  iirc.)

might your system have had a *lot* of memory?  ours tend to be 
fairly modest (32-64G, dual-socket intel.)

thanks,
Mark Hahn | SHARCnet Sysadmin | hahn at sharcnet.ca | http://www.sharcnet.ca
           | McMaster RHPCS    | hahn at mcmaster.ca | 905 525 9140 x24687
           | Compute/Calcul Canada                | http://www.computecanada.ca