[Lustre-discuss] Slow Directory Listing

[Michael Barnes]

Another thing to try is setting vfs_cache_pressure=0 on the OSSes and
periodically setting it to nonzero to reclaim memory.  More details
here:

  http://www.olcf.ornl.gov/wp-content/events/lug2011/4-14-2011/830-900_Robin_Humble_rjh.lug2011.pdf

-mb

On Sep 6, 2011, at 2:43 AM, Indivar Nair wrote:

> Hi ...,
> 
> I have a lustre storage that stores lots of small files i.e. hundreds to
> thousand of 9MB image files.
> While normal file access works fine, the directory listing is extremely
> slow.
> Depending on the number of files in a directory, the listing takes around 5
> - 15 secs.
> 
> I tried 'ls --color=none' and it worked fine; listed the contents
> immediately.
> 
> But that doesn't help my cause. I have Samba Gateway Servers, and all users
> access the storage through the gateway. Double clicking on directory takes a
> long long time to display.
> 
> The cluster consist of -
> - two DRBD Mirrored MDS Servers (Dell R610s) with 10K RPM disks
> - four OSS Nodes (2 Node Cluster (Dell R710s) with a common storage (Dell
> MD3200))
> 
> The storage consists of 12 x 1TB HDDs on both arrays, in RAID 6
> Configuration.
> 
> What actually happens when one does a listing like this?
> What can I do to make the listing faster?
> Could it be an MDS issue?
> Some site suggested that this could be caused due to '-o flock' switch. Is
> it so?
> 
> Kindly Help.
> The storage is in Production, and this is causing a lot of issues.
> 
> Regards,
> 
> 
> Indivar Nair
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss

--
+-----------------------------------------------
| Michael Barnes
|
| Thomas Jefferson National Accelerator Facility
| Scientific Computing Group
| 12000 Jefferson Ave.
| Newport News, VA 23606
| (757) 269-7634
+-----------------------------------------------