Hi, this problem is most likely caused by the XFS speculative preallocation ( https://linux-xfs.oss.sgi.narkive.com/jjjfnyI1/faq-xfs-speculative-preallocation )
Regards, Xavi On Sat, Feb 5, 2022 at 10:19 AM Strahil Nikolov <hunter86...@yahoo.com> wrote: > It seems quite odd. > I'm adding the devel list,as it looks like a bug - but it could be a > feature ;) > > Best Regards, > Strahil Nikolov > > > ----- Препратено съобщение ----- > *От:* Fox <foxxz....@gmail.com> > *До:* Gluster Users <gluster-us...@gluster.org> > *Изпратено:* събота, 5 февруари 2022 г., 05:39:36 Гринуич+2 > *Тема:* Re: [Gluster-users] Distributed-Disperse Shard Behavior > > I tried setting the shard size to 512MB. It slightly improved the space > utilization during creation - not quite double space utilization. And I > didn't run out of space creating a file that occupied 6gb of the 8gb volume > (and I even tried 7168MB just fine). See attached command line log. > > On Fri, Feb 4, 2022 at 6:59 PM Strahil Nikolov <hunter86...@yahoo.com> > wrote: > > It sounds like a bug to me. > In virtualization sharding is quite common (yet, on replica volumes) and I > have never observed such behavior. > Can you increase the shard size to 512M and check if the situation is > better ? > Also, share the volume info. > > Best Regards, > Strahil Nikolov > > On Fri, Feb 4, 2022 at 22:32, Fox > <foxxz....@gmail.com> wrote: > Using gluster v10.1 and creating a Distributed-Dispersed volume with > sharding enabled. > > I create a 2gb file on the volume using the 'dd' tool. The file size shows > 2gb with 'ls'. However, 'df' shows 4gb of space utilized on the volume. > After several minutes the volume utilization drops to the 2gb I would > expect. > > This is repeatable for different large file sizes and different > disperse/redundancy brick configurations. > > I've also encountered a situation, as configured above, where I utilize > close to full disk capacity and am momentarily unable to delete the file. > > I have attached a command line log of an example of above using a set of > test VMs setup in a glusterfs cluster. > > Is this initial 2x space utilization anticipated behavior for sharding? > > It would mean that I can never create a file bigger than half my volume > size as I get an I/O error with no space left on disk. > ________ > > > > Community Meeting Calendar: > > Schedule - > Every 2nd and 4th Tuesday at 14:30 IST / 09:00 UTC > Bridge: https://meet.google.com/cpu-eiue-hvk > Gluster-users mailing list > gluster-us...@gluster.org > https://lists.gluster.org/mailman/listinfo/gluster-users > > ________ > > > > Community Meeting Calendar: > > Schedule - > Every 2nd and 4th Tuesday at 14:30 IST / 09:00 UTC > Bridge: https://meet.google.com/cpu-eiue-hvk > Gluster-users mailing list > gluster-us...@gluster.org > https://lists.gluster.org/mailman/listinfo/gluster-users > ________ > > > > Community Meeting Calendar: > > Schedule - > Every 2nd and 4th Tuesday at 14:30 IST / 09:00 UTC > Bridge: https://meet.google.com/cpu-eiue-hvk > Gluster-users mailing list > gluster-us...@gluster.org > https://lists.gluster.org/mailman/listinfo/gluster-users >
------- Community Meeting Calendar: Schedule - Every 2nd and 4th Tuesday at 14:30 IST / 09:00 UTC Bridge: https://meet.google.com/cpu-eiue-hvk Gluster-devel mailing list Gluster-devel@gluster.org https://lists.gluster.org/mailman/listinfo/gluster-devel