On 04/13/17 23:50, Pranith Kumar Karampuri wrote:> > > On Sat, Apr 8, 2017 at 10:28 AM, Ravishankar N <ravishankar at redhat.com > <mailto:ravishankar at redhat.com>> wrote: > > Hi Pat, > > I'm assuming you are using gluster native (fuse mount). If it > helps, you could try mounting it via gluster NFS (gnfs) and then > see if there is an improvement in speed. Fuse mounts are slower > than gnfs mounts but you get the benefit of avoiding a single > point of failure. Unlike fuse mounts, if the gluster node > containing the gnfs server goes down, all mounts done using that > node will fail). For fuse mounts, you could try tweaking the > write-behind xlator settings to see if it helps. See the > performance.write-behind and performance.write-behind-window-size > options in `gluster volume set help`. Of course, even for gnfs > mounts, you can achieve fail-over by using CTDB. > > > Ravi, > Do you have any data that suggests fuse mounts are slower than > gNFS servers? > > Pat, > I see that I am late to the thread, but do you happen to have > "profile info" of the workload? >I have done actual testing. For directory ops, NFS is faster due to the default cache settings in the kernel. For raw throughput, or ops on an open file, fuse is faster. I have yet to test this but I expect with the newer caching features in 3.8+, even directory op performance should be similar to nfs and more accurate.> You can follow > https://gluster.readthedocs.io/en/latest/Administrator%20Guide/Monitoring%20Workload/ > to get the information. > > > Thanks, > Ravi > > > On 04/08/2017 12:07 AM, Pat Haley wrote: >> >> Hi, >> >> We noticed a dramatic slowness when writing to a gluster disk >> when compared to writing to an NFS disk. Specifically when using >> dd (data duplicator) to write a 4.3 GB file of zeros: >> >> * on NFS disk (/home): 9.5 Gb/s >> * on gluster disk (/gdata): 508 Mb/s >> >> The gluser disk is 2 bricks joined together, no replication or >> anything else. The hardware is (literally) the same: >> >> * one server with 70 hard disks and a hardware RAID card. >> * 4 disks in a RAID-6 group (the NFS disk) >> * 32 disks in a RAID-6 group (the max allowed by the card, >> /mnt/brick1) >> * 32 disks in another RAID-6 group (/mnt/brick2) >> * 2 hot spare >> >> Some additional information and more tests results (after >> changing the log level): >> >> glusterfs 3.7.11 built on Apr 27 2016 14:09:22 >> CentOS release 6.8 (Final) >> RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS-3 >> 3108 [Invader] (rev 02) >> >> >> >> *Create the file to /gdata (gluster)* >> [root at mseas-data2 gdata]# dd if=/dev/zero of=/gdata/zero1 bs=1M >> count=1000 >> 1000+0 records in >> 1000+0 records out >> 1048576000 bytes (1.0 GB) copied, 1.91876 s, *546 MB/s* >> >> *Create the file to /home (ext4)* >> [root at mseas-data2 gdata]# dd if=/dev/zero of=/home/zero1 bs=1M >> count=1000 >> 1000+0 records in >> 1000+0 records out >> 1048576000 bytes (1.0 GB) copied, 0.686021 s, *1.5 GB/s - *3 >> times as fast* >> >> >> Copy from /gdata to /gdata (gluster to gluster) >> *[root at mseas-data2 gdata]# dd if=/gdata/zero1 of=/gdata/zero2 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 101.052 s, *10.4 MB/s* - >> realllyyy slooowww >> >> >> *Copy from /gdata to /gdata* *2nd time *(gluster to gluster)** >> [root at mseas-data2 gdata]# dd if=/gdata/zero1 of=/gdata/zero2 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 92.4904 s, *11.3 MB/s* - >> realllyyy slooowww again >> >> >> >> *Copy from /home to /home (ext4 to ext4)* >> [root at mseas-data2 gdata]# dd if=/home/zero1 of=/home/zero2 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 3.53263 s, *297 MB/s *30 times >> as fast >> >> >> *Copy from /home to /home (ext4 to ext4)* >> [root at mseas-data2 gdata]# dd if=/home/zero1 of=/home/zero3 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 4.1737 s, *251 MB/s* - 30 times >> as fast >> >> >> As a test, can we copy data directly to the xfs mountpoint >> (/mnt/brick1) and bypass gluster? >> >> >> Any help you could give us would be appreciated. >> >> Thanks >> >> -- >> >> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- >> Pat Haley Email:phaley at mit.edu <mailto:phaley at mit.edu> >> Center for Ocean Engineering Phone: (617) 253-6824 >> Dept. of Mechanical Engineering Fax: (617) 253-8125 >> MIT, Room 5-213http://web.mit.edu/phaley/www/ >> 77 Massachusetts Avenue >> Cambridge, MA 02139-4301 >> >> _______________________________________________ >> Gluster-users mailing list >> Gluster-users at gluster.org <mailto:Gluster-users at gluster.org> >> http://lists.gluster.org/mailman/listinfo/gluster-users >> <http://lists.gluster.org/mailman/listinfo/gluster-users> > > _______________________________________________ Gluster-users > mailing list Gluster-users at gluster.org > <mailto:Gluster-users at gluster.org> > http://lists.gluster.org/mailman/listinfo/gluster-users > <http://lists.gluster.org/mailman/listinfo/gluster-users> > > -- > Pranith > > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://lists.gluster.org/mailman/listinfo/gluster-users-------------- next part -------------- An HTML attachment was scrubbed... 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Pranith Kumar Karampuri
2017-May-17 09:02 UTC
[Gluster-users] Slow write times to gluster disk
On Tue, May 16, 2017 at 9:38 PM, Joe Julian <joe at julianfamily.org> wrote:> On 04/13/17 23:50, Pranith Kumar Karampuri wrote: > > > > On Sat, Apr 8, 2017 at 10:28 AM, Ravishankar N <ravishankar at redhat.com> > wrote: > >> Hi Pat, >> >> I'm assuming you are using gluster native (fuse mount). If it helps, you >> could try mounting it via gluster NFS (gnfs) and then see if there is an >> improvement in speed. Fuse mounts are slower than gnfs mounts but you get >> the benefit of avoiding a single point of failure. Unlike fuse mounts, if >> the gluster node containing the gnfs server goes down, all mounts done >> using that node will fail). For fuse mounts, you could try tweaking the >> write-behind xlator settings to see if it helps. See the >> performance.write-behind and performance.write-behind-window-size >> options in `gluster volume set help`. Of course, even for gnfs mounts, you >> can achieve fail-over by using CTDB. >> > > Ravi, > Do you have any data that suggests fuse mounts are slower than gNFS > servers? > > Pat, > I see that I am late to the thread, but do you happen to have > "profile info" of the workload? > > > I have done actual testing. For directory ops, NFS is faster due to the > default cache settings in the kernel. For raw throughput, or ops on an open > file, fuse is faster. > > I have yet to test this but I expect with the newer caching features in > 3.8+, even directory op performance should be similar to nfs and more > accurate. >We are actually comparing fuse+gluster and kernel NFS (n the same brick. Did you get a chance to do this test at any point?> > > You can follow https://gluster.readthedocs.io/en/latest/Administrator% > 20Guide/Monitoring%20Workload/ to get the information. > > >> >> Thanks, >> Ravi >> >> >> On 04/08/2017 12:07 AM, Pat Haley wrote: >> >> >> Hi, >> >> We noticed a dramatic slowness when writing to a gluster disk when >> compared to writing to an NFS disk. Specifically when using dd (data >> duplicator) to write a 4.3 GB file of zeros: >> >> - on NFS disk (/home): 9.5 Gb/s >> - on gluster disk (/gdata): 508 Mb/s >> >> The gluser disk is 2 bricks joined together, no replication or anything >> else. The hardware is (literally) the same: >> >> - one server with 70 hard disks and a hardware RAID card. >> - 4 disks in a RAID-6 group (the NFS disk) >> - 32 disks in a RAID-6 group (the max allowed by the card, >> /mnt/brick1) >> - 32 disks in another RAID-6 group (/mnt/brick2) >> - 2 hot spare >> >> Some additional information and more tests results (after changing the >> log level): >> >> glusterfs 3.7.11 built on Apr 27 2016 14:09:22 >> CentOS release 6.8 (Final) >> RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS-3 3108 >> [Invader] (rev 02) >> >> >> >> *Create the file to /gdata (gluster)* >> [root at mseas-data2 gdata]# dd if=/dev/zero of=/gdata/zero1 bs=1M >> count=1000 >> 1000+0 records in >> 1000+0 records out >> 1048576000 bytes (1.0 GB) copied, 1.91876 s, *546 MB/s* >> >> *Create the file to /home (ext4)* >> [root at mseas-data2 gdata]# dd if=/dev/zero of=/home/zero1 bs=1M count=1000 >> 1000+0 records in >> 1000+0 records out >> 1048576000 bytes (1.0 GB) copied, 0.686021 s, *1.5 GB/s - *3 times as >> fast >> >> >> >> * Copy from /gdata to /gdata (gluster to gluster) *[root at mseas-data2 >> gdata]# dd if=/gdata/zero1 of=/gdata/zero2 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 101.052 s, *10.4 MB/s* - realllyyy >> slooowww >> >> >> *Copy from /gdata to /gdata* *2nd time (gluster to gluster)* >> [root at mseas-data2 gdata]# dd if=/gdata/zero1 of=/gdata/zero2 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 92.4904 s, *11.3 MB/s* - realllyyy >> slooowww again >> >> >> >> *Copy from /home to /home (ext4 to ext4)* >> [root at mseas-data2 gdata]# dd if=/home/zero1 of=/home/zero2 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 3.53263 s, *297 MB/s *30 times as fast >> >> >> *Copy from /home to /home (ext4 to ext4)* >> [root at mseas-data2 gdata]# dd if=/home/zero1 of=/home/zero3 >> 2048000+0 records in >> 2048000+0 records out >> 1048576000 bytes (1.0 GB) copied, 4.1737 s, *251 MB/s* - 30 times as fast >> >> >> As a test, can we copy data directly to the xfs mountpoint (/mnt/brick1) >> and bypass gluster? >> >> >> Any help you could give us would be appreciated. >> >> Thanks >> >> -- >> >> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- >> Pat Haley Email: phaley at mit.edu >> Center for Ocean Engineering Phone: (617) 253-6824 >> Dept. of Mechanical Engineering Fax: (617) 253-8125 >> MIT, Room 5-213 http://web.mit.edu/phaley/www/ >> 77 Massachusetts Avenue >> Cambridge, MA 02139-4301 >> >> _______________________________________________ >> Gluster-users mailing listGluster-users at gluster.orghttp://lists.gluster.org/mailman/listinfo/gluster-users >> >> _______________________________________________ Gluster-users mailing >> list Gluster-users at gluster.org http://lists.gluster.org/mailm >> an/listinfo/gluster-users > > -- > Pranith > > _______________________________________________ > Gluster-users mailing listGluster-users at gluster.orghttp://lists.gluster.org/mailman/listinfo/gluster-users > > > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://lists.gluster.org/mailman/listinfo/gluster-users >-- Pranith -------------- next part -------------- An HTML attachment was scrubbed... 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