[gpfsug-discuss] Trapped Inodes - releases, now count them properly!

Mon Jul 4 10:44:02 BST 2016

Hi Marc,

Thanks again for the suggestions. An interesting report in the log while the another node took over managing the filesystem:

Mon Jul  4 10:24:08.616 2016: [W] Inode space 10 in file system gpfs is approaching the limit for the maximum number of inodes.

Inode space 10 was the independent fileset that the snapshot creation/deletion managed to remove. Still getting negative inode numbers reported after migrating manager functions and suspending/resuming the file system:

Inode Information
-----------------
Total number of used inodes in all Inode spaces:         -103900000
Total number of free inodes in all Inode spaces:          -24797856
Total number of allocated inodes in all Inode spaces:    -128697856
Total of Maximum number of inodes in all Inode spaces:   -103900000

I’ll have to wait until later today to try unmounting, daemon recycle or mmfsck.

Cheers,
Luke.

From: gpfsug-discuss-bounces at spectrumscale.org [mailto:gpfsug-discuss-bounces at spectrumscale.org] On Behalf Of Marc A Kaplan
Sent: 03 July 2016 19:43
To: gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
Subject: Re: [gpfsug-discuss] Trapped Inodes - releases, now count them properly!

mmdf statistics are not real-time accurate, there is a trade off in accuracy vs the cost of polling each node that might have the file system mounted.

That said, here are some possibilities, in increasing order of impact on users and your possible desperation ;-)

A1. Wait a while (at most a few minutes) and see if the mmdf stats are updated.

A2.
mmchmgr fs another-node

may force new stats to be sent to the new fs manager. (Not sure but I expect it will.)

B. Briefly quiesce the file system with:

mmfsctl fs suspend; mmfsctl fs resume;

C. If you have no users active ... I'm pretty sure

mmumount fs -a ; mmmount fs -a;

will  clear the problem ... but there's always

D.
mmshutdown -a ; mmstartup -a

E.
If none of those resolve the situation something is hosed --

F.
hope that

mmfsck

can fix it.

--marc

From:        Luke Raimbach <Luke.Raimbach at crick.ac.uk<mailto:Luke.Raimbach at crick.ac.uk>>
To:        gpfsug main discussion list <gpfsug-discuss at spectrumscale.org<mailto:gpfsug-discuss at spectrumscale.org>>
Date:        07/03/2016 10:55 AM
Subject:        Re: [gpfsug-discuss] Trapped Inodes
Sent by:        gpfsug-discuss-bounces at spectrumscale.org<mailto:gpfsug-discuss-bounces at spectrumscale.org>
________________________________

Hi Marc,

Thanks for that suggestions. This seems to have removed the NULL fileset from the list, however mmdf now shows even more strange statistics:

Inode Information
-----------------
Total number of used inodes in all Inode spaces:         -103900000
Total number of free inodes in all Inode spaces:          -24797856
Total number of allocated inodes in all Inode spaces:    -128697856
Total of Maximum number of inodes in all Inode spaces:   -103900000

Any ideas why these negative numbers are being reported?

Cheers,
Luke.

From: gpfsug-discuss-bounces at spectrumscale.org<mailto:gpfsug-discuss-bounces at spectrumscale.org> [mailto:gpfsug-discuss-bounces at spectrumscale.org] On Behalf Of Marc A Kaplan
Sent: 02 July 2016 20:17
To: gpfsug main discussion list <gpfsug-discuss at spectrumscale.org<mailto:gpfsug-discuss at spectrumscale.org>>
Subject: Re: [gpfsug-discuss] Trapped Inodes

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<mailto:Luke.Raimbach at crick.ac.uk>>
To:        gpfsug main discussion list <gpfsug-discuss at spectrumscale.org<mailto: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<mailto: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<mailto: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<mailto:Luke.Raimbach at crick.ac.uk>>
To:        gpfsug main discussion list <gpfsug-discuss at spectrumscale.org<mailto: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<mailto: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<mailto: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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