All,
Likely not an answer to these situations, but a fix was introduced in 5.0.4.4 (APAR IJ22894) and 4.2.3.22 (APAR IJ24661) to address a (long-standing) problem where mmcheckquota would compute quotas incorrectly in file systems where metadata pool and data pool subblocksizes are different.
Felipe
----
Felipe Knop [email protected]
GPFS Development and Security
IBM Systems
IBM Building 008
2455 South Rd, Poughkeepsie, NY 12601
(845) 433-9314 T/L 293-9314
Felipe Knop [email protected]
GPFS Development and Security
IBM Systems
IBM Building 008
2455 South Rd, Poughkeepsie, NY 12601
(845) 433-9314 T/L 293-9314
----- Original message -----
From: Jaime Pinto <[email protected]>
Sent by: [email protected]
To: [email protected]
Cc:
Subject: [EXTERNAL] Re: [gpfsug-discuss] SS 5.0.x and quota issues
Date: Mon, May 18, 2020 9:56 AM
So Bob,
Yes, we too have observed an uncharacteristic lag on the correction of the internal quota accounting on GPFS since we updated from version 3.3 to version 4.x some 7-8 years ago. That lag remains through version 5.0.x as well. And it persisted through several appliances (DDN, G200, GSS, ESS and now DSS-G). In our university environment there is also a lot of data churning, in particular small files.
The workaround has always been to periodically run mmcheckquota on the top independent fileset to expedite that correction (I have a crontab script that measures the relative size of the in-dought columns on the mmrepquota report, size and inodes, and if either exceeds 2% for any USR/GRP/FILESET I run mmrepquota)
We have opened supports calls with IBM about this issue in the past, and we never got a solution, to possibly adjust some GPFS configuration parameter, and have this correction done automatically. We gave up.
And that begs the question: what do you mean by "... 5.0.4-4 ... that has a fix for mmcheckquota"? Isn't mmcheckquota zeroing the in-doubt columns when you run it?
The fix should be for gpfs (something buried in the code over many versions). As far as I can tell there has never been anything wrong with mmcheckquota.
Thanks
Jaime
On 5/18/2020 08:59:09, Cregan, Bob wrote:
> Hi,
> At Imperial we have been experiencing an issue with SS 5.0.x and quotas. The main symptom is a slow decay in the accuracy of reported quota usage when compared to the actual usage as reported by "du". This discrepancy can be as little as a few percent and as much as many X100% . We also sometimes see bizarre effects such negative file number counts being reported.
>
> We have been working with IBM and have put in the latest 5.0.4-4 (that has a fix for mmcheckquota) that we have been pinning our hopes on, but this has not worked.
>
> Is anyone else experiencing similar issues? We need to try and get an idea if this is an issue peculiar to our set up or a more general SS problem.
>
> We are using user and group quotas in a fileset context.
>
> Thanks
>
>
> *Bob Cregan*
> HPC Systems Analyst
>
> Information & Communication Technologies
>
> Imperial College London,
> South Kensington Campus London, SW7 2AZ
> T: 07712388129
> E: [email protected]
>
> W: www.imperial.ac.uk/ict/rcs <http://www.imperial.ac.uk/ict/rcs >
>
> _1505984389175_twitter.png @imperialRCS @imperialRSE
>
> 1505983882959_Imperial-RCS.png
>
>
>
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