[Gluster-users] [Gluster-devel] cannot delete non-empty directory

[Shyam]

On 02/08/2015 12:19 PM, David F. Robinson wrote:
> I am seeing these messsages after I delete large amounts of data using
> gluster 3.6.2.
> cannot delete non-empty directory:
> old_shelf4/Aegis/!!!Programs/RavenCFD/Storage/Jimmy_Old/src_vj1.5_final
> *_From the FUSE mount (as root), the directory shows up as empty:_*
> # pwd
> /backup/homegfs/backup.0/old_shelf4/Aegis/!!!Programs/RavenCFD/Storage/Jimmy_Old/src_vj1.5_final
>
> # ls -al
> total 5
> d--------- 2 root root    4106 Feb  6 13:55 .
> drwxrws--- 3  601 dmiller   72 Feb  6 13:55 ..
> However, when you look at the bricks, the files are still there (none on
> brick01bkp, all files are on brick02bkp).  All of the files are 0-length
> and have ------T permissions.

These files are linkto files that are created by DHT, which basically 
mean the files were either renamed, or the brick layout changed (I 
suspect the former to be the cause).

These files should have been deleted when the files that they point to 
were deleted, looks like this did not happen.

Can I get the following information for some of the files here,
- getfattr -d -m . -e text <path to file on brick>
   - The output of trusted.glusterfs.dht.linkto xattr should state where 
the real file belongs, in this case as there are only 2 bricks, it 
should be brick01bkp subvol
- As the second brick is empty, we should be able to safely delete these 
files from the brick and proceed to do an rmdir on the mount point of 
the volume as the directory is now empty.
- Please check, the one sub-directory that is showing up in this case as 
well, "save1"

> Any suggestions on how to fix this and how to prevent it from happening?

I believe there are renames happening here, possibly by the archive 
creator, one way to prevent the rename from creating a linkto file is to 
use the DHT set parameter to set a pattern so that file name hash 
considers only the static part of the name.

The set parameter is, cluster.extra-hash-regex.

A link on a similar problem and how to use this set parameter (there a 
few in the gluster forums) would be, 
http://www.gluster.org/pipermail/gluster-devel/2014-November/042863.html

Additionally, there is a bug here, the unlink of the file should have 
cleaned up the linkto as well, so that all of the above is not required, 
we have noticed this with NFS and FUSE mounts (ref bugs, 1117923, 
1139992), and investigation is in progress on the same. We will step up 
the priority on this so that we have a clean fix that can be used to 
prevent this in the future.

Shyam