[gpfsug-discuss] Trapped Inodes

[Marc A Kaplan]

I have been informed that it is possible that a glitch can occur (for 
example an abrupt shutdown) which can leave you in a situation where it 
looks like all snapshots are deleted, but there is still a hidden snapshot 
that must be cleaned up... 

The workaround is to create a snapshot `mmcrsnapshot fs dummy`  and then 
delete it `mmdelsnapshot fs dummy` and see if that clears up the 
situation...

--marc



From:   Luke Raimbach <Luke.Raimbach at crick.ac.uk>
To:     gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
Date:   07/02/2016 06:05 AM
Subject:        Re: [gpfsug-discuss] Trapped Inodes
Sent by:        gpfsug-discuss-bounces at spectrumscale.org



Hi Marc,
Thanks for the suggestion.
Snapshots were my first suspect but there are none anywhere on the 
filesystem.
Cheers,
Luke.
On 1 Jul 2016 5:30 pm, Marc A Kaplan <makaplan at us.ibm.com> wrote:
Question and Suggestion:  Do you have any snapshots that might include 
files that were in the fileset you are attempting to delete?  Deleting 
those snapshots will allow the fileset deletion to complete.  The 
snapshots are kinda intertwined with what was the "live" copy of the 
inodes. In the GPFS "ditto" implementation of snapshotting,  for a file 
that has not changed since the snapshot operation, the snapshot copy is 
not really a copy but just a pointer to the "live" file.   So even after 
you have logically deleted the "live" files, the snapshot still points to 
those inodes you thought you deleted.  Rather than invalidate the 
snapshot, (you wouldn't want that, would you?!) GPFS holds onto the 
inodes, until they are no longer referenced by any snapshot.

--marc 



From:        Luke Raimbach <Luke.Raimbach at crick.ac.uk>
To:        gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
Date:        07/01/2016 06:32 AM
Subject:        [gpfsug-discuss] Trapped Inodes
Sent by:        gpfsug-discuss-bounces at spectrumscale.org



Hi All,

I've run out of inodes on a relatively small filesystem. The total 
metadata capacity allows for a maximum of 188,743,680 inodes.

A fileset containing 158,000,000 inodes was force deleted and has gone 
into a bad state, where it is reported as (NULL) and has state "deleted":

Attributes for fileset (NULL):
===============================
Status                                  Deleted
Path                                    --
Id                                      15
Root inode                              latest:
Parent Id                               <none>
Created                                 Wed Jun 15 14:07:51 2016
Comment
Inode space                             8
Maximum number of inodes                158000000
Allocated inodes                        158000000
Permission change flag                  chmodAndSetacl
afm-associated                          No

Offline mmfsck fixed a few problems, but didn't free these poor, trapped 
inodes. Now I've run out and mmdf is telling me crazy things like this:

Inode Information
-----------------
Total number of used inodes in all Inode spaces:                  0
Total number of free inodes in all Inode spaces:           27895680
Total number of allocated inodes in all Inode spaces:      27895680
Total of Maximum number of inodes in all Inode spaces:     34100000


Current GPFS build: "4.2.0.3".

Who will help me rescue these inodes?

Cheers,
Luke.

Luke Raimbach​
Senior HPC Data and Storage Systems Engineer,
The Francis Crick Institute,
Gibbs Building,
215 Euston Road,
London NW1 2BE.

E: luke.raimbach at crick.ac.uk
W: www.crick.ac.uk

The Francis Crick Institute Limited is a registered charity in England and 
Wales no. 1140062 and a company registered in England and Wales no. 
06885462, with its registered office at 215 Euston Road, London NW1 2BE.
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The Francis Crick Institute Limited is a registered charity in England and 
Wales no. 1140062 and a company registered in England and Wales no. 
06885462, with its registered office at 215 Euston Road, London NW1 2BE. 
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gpfsug-discuss mailing list
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