Strahil Nikolov
2022-Feb-05 09:19 UTC
[Gluster-users] Fw: Distributed-Disperse Shard Behavior
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
----- ?????????? ????????? ----- ??: Fox <foxxz.net at gmail.com>??:
Gluster Users <gluster-users at gluster.org>?????????: ??????, 5 ????????
2022 ?., 05:39:36 ???????+2????: 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_bg at 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.net at 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.________
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________
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Xavi Hernandez
2022-Feb-09 15:00 UTC
[Gluster-users] Fw: Distributed-Disperse Shard Behavior
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_bg at 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 > > > ----- ?????????? ????????? ----- > *??:* Fox <foxxz.net at gmail.com> > *??:* Gluster Users <gluster-users at gluster.org> > *?????????:* ??????, 5 ???????? 2022 ?., 05:39:36 ???????+2 > *????:* 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_bg at 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.net at 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-users at 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-users at 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-users at gluster.org > https://lists.gluster.org/mailman/listinfo/gluster-users >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.gluster.org/pipermail/gluster-users/attachments/20220209/4de43404/attachment.html>