Re: deep chmod|chown -R begin to start OOMkiller

[Eric Sandeen <sandeen@xxxxxxx>]

CHIKAMA masaki wrote:
> Ok. I understand.
> But sorry, this is not an acceptable option now,
> because I have already filled half of 10TB by data.
> I'll be happy if 'xfs_growfs -l" option is implemented.
>
> Anyway, thank you for your advice.
With some careful, very-much-unsupported use of xfs_db, you could shrink the 
log while offline.  It's not supported, and I'd feel a bit frightened of doing 
this with a large important filesystem.
But essentially you -could- follow this procedure:

Unmount the filesystem so that the log is clean.
run xfs_repair -L to zero out the log.
run xfs_db to change "logblocks" in each superblock to a smaller value
 - do NOT change the "logstart" or any other superblock values
cross your fingers & remount

I haven't tested this locally, at least not recently.  You didn't hear this 
from me, and if it breaks, you get to keep both pieces... at a minimum you 
might wait for David or Nathan to chime in and sanity-check my suggestion.  And 
even if they say it seems reasonable, I'd suggest testing on an unimportant 
filesystem a few times to be sure.
-Eric