[Lustre-discuss] questions about an OST content

[Joe Landman]

On 11/06/2010 10:24 AM, Bob Ball wrote:
> I am emptying a set of OST so that I can reformat the underlying RAID-6
> more efficiently.  Two questions:
> 1. Is there a quick way to tell if the OST is really empty?  lfs_find
> takes many hours to run.

Yes ...

	df -H /path/to/OST/mount_point

if you have more than a few megabytes in the used column, it is probably 
in use.  There are other mechanisms, but we find this one works quickest 
to get a baseline read of how full the OST is.

[...]

> /dev/sdj              3.5T  3.1T  222G  94% /mnt/ost51
>    10 UP obdfilter umt3-OST0018 umt3-OST0018_UUID 547
> umt3-OST0018_UUID           3.4T        3.0T      221.1G  88%
> /lustre/umt3[OST:24]
>    20 IN osc umt3-OST0018-osc umt3-mdtlov_UUID 5

This suggests you are at about 90% utilization of this OST (/dev/sdj)


-- 
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics, Inc.
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