Re: xfs metadata overhead

[Dave Chinner <david@xxxxxxxxxxxxx>]

On Fri, Jun 24, 2016 at 04:21:39PM +0300, Danny Shavit wrote:
> I see.
> So using bulk_stat ioctl in similar way to xfs_fsr and summing allocated
> size will result with  more accurate number?

No. du includes *directory blocks* in it's sum. bulkstat only counts
inodes, which is not counted by du and is part of the metadata you
have already accounted for. Even then, bulkstat doesn't give an
accurate account o space used by inodes because they can be sparsely
allocated from within inode chunks.

Just snapshot the volume, run metadump on the snapshot - it's the
fastest, most reliable way to work out how much metadata is in a
filesystem right now...

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx