Just to chime in on this... We have experienced a lot of problems as a result of the independent fileset limitation @ 1000. We have a very large campus wide deployment that relies upon filesets for collection management of large (and small) scientific data outputs. Every human who uses our GPFS AFM fabric gets a "collection", which is an independent fileset. Some may say this was an unwise design choice - but it was deliberate and related to security, namespace and inode isolation. It is a considered decision. Just not considered _enough_ given the 1000 fileset limit ;).
We've even had to go as far as re-organising entire filesystems (splitting things apart) to sacrifice performance (less spindles for the filesets on top of a filesystem) to work around it - and sometimes spill into entirely new arrays. I've had it explained to me by internal IBM staff *why* it is hard to fix the fileset limits - and it isn't as straightforward as people think - especially in our case where each fileset is an AFM cache/home relationship - but we desperately need a solution. We logged an RFE. Hopefully others do, also. The complexity has been explained to me by a very good colleague who has helped us a great deal inside IBM (name withheld to protect the innocent) as a knock on effect of the computational overhead and expense of things _associated_ with independent filesets, like recursing a snapshot tree. So - it really isn't as simple as things appear on the surface - but it doesn't mean we shouldn't try to fix it, I suppose! We'd love to see this improved, too - as it's currently making things difficult. Happy to collaborate and work together on this, as always. -jc ---------------------------------------------------------------------- Message: 1 Date: Fri, 10 Aug 2018 11:22:23 -0400 From: Doug Johnson <[email protected]> Hi all, I want to chime in because this is precisely what we have done at OSC due to the same motivations Janell described. Our design was based in part on the guidelines in the "Petascale Data Protection" white paper from IBM. We only have ~200 filesets and 250M inodes today, but expect to grow. We are also very interested in details about performance issues and independent filesets. Can IBM elaborate? Best, Doug Martin Lischewski <[email protected]> writes: > Hello Olaf, hello Marc, > > we in J?lich are in the middle of migrating/copying all our old > filesystems which were created with filesystem > version: 13.23 (3.5.0.7) to new filesystems created with GPFS 5.0.1. > > We move to new filesystems mainly for two reasons: 1. We want to use the new > increased number of subblocks. > 2. We have to change our quota from normal "group-quota per filesystem" to > "fileset-quota". > > The idea is to create a separate fileset for each group/project. For > the users the quota-computation should be much more transparent. From > now on all data which is stored inside of their directory (fileset) counts > for their quota independent of the ownership. > > Right now we have round about 900 groups which means we will create round > about 900 filesets per filesystem. > In one filesystem we will have about 400million inodes (with rising tendency). > > This filesystem we will back up with "mmbackup" so we talked with > Dominic Mueller-Wicke and he recommended us to use independent > filesets. Because then the policy-runs can be parallelized and we can > increase the backup performance. We belive that we require these parallelized > policies run to meet our backup performance targets. > > But there are even more features we enable by using independet > filesets. E.g. "Fileset level snapshots" and "user and group quotas inside of > a fileset". > > I did not know about performance issues regarding independent > filesets... Can you give us some more information about this? > > All in all we are strongly supporting the idea of increasing this limit. > > Do I understand correctly that by opening a PMR IBM allows to increase > this limit on special sides? I would rather like to increase the limit and > make it official public available and supported. > > Regards, > > Martin > > Am 10.08.2018 um 14:51 schrieb Olaf Weiser: > > Hallo Stephan, > the limit is not a hard coded limit - technically spoken, you can raise it > easily. > But as always, it is a question of test 'n support .. > > I've seen customer cases, where the use of much smaller amount of > independent filesets generates a lot performance issues, hangs ... at least > noise and partial trouble .. > it might be not the case with your specific workload, because due to > the fact, that you 're running already close to 1000 ... > > I suspect , this number of 1000 file sets - at the time of > introducing it - was as also just that one had to pick a number... > > ... turns out.. that a general commitment to support > 1000 > ind.fileset is more or less hard.. because what uses cases should we > test / support I think , there might be a good chance for you , that > for your specific workload, one would allow and support more than > 1000 > > do you still have a PMR for your side for this ? - if not - I know .. > open PMRs is an additional ...but could you please .. > then we can decide .. if raising the limit is an option for you .. > > Mit freundlichen Gr??en / Kind regards > > Olaf Weiser > > EMEA Storage Competence Center Mainz, German / IBM Systems, Storage > Platform, > > ---------------------------------------------------------------------- > --------------------------------------------------------------------- > IBM Deutschland > IBM Allee 1 > 71139 Ehningen > Phone: +49-170-579-44-66 > E-Mail: [email protected] > > ---------------------------------------------------------------------- > --------------------------------------------------------------------- > IBM Deutschland GmbH / Vorsitzender des Aufsichtsrats: Martin Jetter > Gesch?ftsf?hrung: Martina Koederitz (Vorsitzende), Susanne Peter, > Norbert Janzen, Dr. Christian Keller, Ivo Koerner, Markus Koerner > Sitz der Gesellschaft: Ehningen / Registergericht: Amtsgericht > Stuttgart, HRB 14562 / WEEE-Reg.-Nr. DE > 99369940 > > From: "Peinkofer, Stephan" <[email protected]> > To: gpfsug main discussion list <[email protected]> > Cc: Doris Franke <[email protected]>, Uwe Tron > <[email protected]>, Dorian Krause <[email protected]> > Date: 08/10/2018 01:29 PM > Subject: [gpfsug-discuss] GPFS Independent Fileset Limit Sent by: > [email protected] > ---------------------------------------------------------------------- > ----------------------------- > > Dear IBM and GPFS List, > > we at the Leibniz Supercomputing Centre and our GCS Partners from the > J?lich Supercomputing Centre will soon be hitting the current Independent > Fileset Limit of 1000 on a number of our GPFS Filesystems. > > There are also a number of RFEs from other users open, that target this > limitation: > > https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID= > 56780 > > https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID= > 120534 > > https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID= > 106530 > > https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID= > 85282 > > I know GPFS Development was very busy fulfilling the CORAL > requirements but maybe now there is again some time to improve something > else. > > If there are any other users on the list that are approaching the > current limitation in independent filesets, please take some time and vote > for the RFEs above. > > Many thanks in advance and have a nice weekend. > Best Regards, > Stephan Peinkofer > > _______________________________________________ > gpfsug-discuss mailing list > gpfsug-discuss at spectrumscale.org > http://gpfsug.org/mailman/listinfo/gpfsug-discuss > > _______________________________________________ > gpfsug-discuss mailing list > gpfsug-discuss at spectrumscale.org > http://gpfsug.org/mailman/listinfo/gpfsug-discuss ------------------------------ Message: 2 Date: Fri, 10 Aug 2018 16:01:17 +0000 From: Bryan Banister <[email protected]> To: gpfsug main discussion list <[email protected]> Subject: Re: [gpfsug-discuss] GPFS Independent Fileset Limit Message-ID: <[email protected]> Content-Type: text/plain; charset="iso-8859-1" Just as a follow up to my own note, Stephan, already provided a list of existing RFEs from which to vote through the IBM RFE site, cheers, -Bryan From: [email protected] <[email protected]> On Behalf Of Bryan Banister Sent: Friday, August 10, 2018 10:51 AM To: gpfsug main discussion list <[email protected]> Subject: Re: [gpfsug-discuss] GPFS Independent Fileset Limit Note: External Email ________________________________ This is definitely a great candidate for a RFE, if one does not already exist. Not to try and contradict by friend Olaf here, but I have been talking a lot with those internal to IBM, and the PMR process is for finding and correcting operational problems with the code level you are running, and closing out the PMR as quickly as possible. PMRs are not the vehicle for getting substantive changes and enhancements made to the product in general, which the RFE process is really the main way to do this. I just got off a call with Kristie and Carl about the RFE process and those on the list may know that we are working to improve this overall process. More will be sent out about this in the near future!! So I thought I would chime in on this discussion here to hopefully help us understand how important the RFE (admittedly currently got great) process really is and will be a great way to work together on these common goals and needs for the product we rely so heavily upon! Cheers!! -Bryan From: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> On Behalf Of Peinkofer, Stephan Sent: Friday, August 10, 2018 10:40 AM To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Subject: Re: [gpfsug-discuss] GPFS Independent Fileset Limit Note: External Email ________________________________ Dear Olaf, I know that this is "just" a "support" limit. However Sven some day on a UG meeting in Ehningen told me that there is more to this than just adjusting your QA qualification tests since the way it is implemented today does not really scale ;). That's probably the reason why you said you see sometimes problems when you are not even close to the limit. So if you look at the 250PB Alpine file system of Summit today, that is what's going to deployed at more than one site world wide in 2-4 years and imho independent filesets are a great way to make this large systems much more handy while still maintaining a unified namespace. So I really think it would be beneficial if the architectural limit that prevents scaling the number of independent filesets could be removed at all. Best Regards, Stephan Peinkofer ________________________________ From: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> on behalf of Olaf Weiser <[email protected]<mailto:[email protected]>> Sent: Friday, August 10, 2018 2:51 PM To: gpfsug main discussion list Cc: [email protected]<mailto:[email protected]>; Doris Franke; Uwe Tron; Dorian Krause Subject: Re: [gpfsug-discuss] GPFS Independent Fileset Limit Hallo Stephan, the limit is not a hard coded limit - technically spoken, you can raise it easily. But as always, it is a question of test 'n support .. I've seen customer cases, where the use of much smaller amount of independent filesets generates a lot performance issues, hangs ... at least noise and partial trouble .. it might be not the case with your specific workload, because due to the fact, that you 're running already close to 1000 ... I suspect , this number of 1000 file sets - at the time of introducing it - was as also just that one had to pick a number... ... turns out.. that a general commitment to support > 1000 ind.fileset is more or less hard.. because what uses cases should we test / support I think , there might be a good chance for you , that for your specific workload, one would allow and support more than 1000 do you still have a PMR for your side for this ? - if not - I know .. open PMRs is an additional ...but could you please .. then we can decide .. if raising the limit is an option for you .. Mit freundlichen Gr??en / Kind regards Olaf Weiser EMEA Storage Competence Center Mainz, German / IBM Systems, Storage Platform, ------------------------------------------------------------------------------------------------------------------------------------------- IBM Deutschland IBM Allee 1 71139 Ehningen Phone: +49-170-579-44-66 E-Mail: [email protected]<mailto:[email protected]> ------------------------------------------------------------------------------------------------------------------------------------------- IBM Deutschland GmbH / Vorsitzender des Aufsichtsrats: Martin Jetter Gesch?ftsf?hrung: Martina Koederitz (Vorsitzende), Susanne Peter, Norbert Janzen, Dr. Christian Keller, Ivo Koerner, Markus Koerner Sitz der Gesellschaft: Ehningen / Registergericht: Amtsgericht Stuttgart, HRB 14562 / WEEE-Reg.-Nr. DE 99369940 From: "Peinkofer, Stephan" <[email protected]<mailto:[email protected]>> To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Cc: Doris Franke <[email protected]<mailto:[email protected]>>, Uwe Tron <[email protected]<mailto:[email protected]>>, Dorian Krause <[email protected]<mailto:[email protected]>> Date: 08/10/2018 01:29 PM Subject: [gpfsug-discuss] GPFS Independent Fileset Limit Sent by: [email protected]<mailto:[email protected]> ________________________________ Dear IBM and GPFS List, we at the Leibniz Supercomputing Centre and our GCS Partners from the J?lich Supercomputing Centre will soon be hitting the current Independent Fileset Limit of 1000 on a number of our GPFS Filesystems. There are also a number of RFEs from other users open, that target this limitation: https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=56780 Sign up for an IBM account<https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=56780> www.ibm.com<http://www.ibm.com> IBM account registration https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=120534 https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=106530 https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=85282 I know GPFS Development was very busy fulfilling the CORAL requirements but maybe now there is again some time to improve something else. If there are any other users on the list that are approaching the current limitation in independent filesets, please take some time and vote for the RFEs above. Many thanks in advance and have a nice weekend. 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