On Wed, May 17, 2017 at 9:54 PM, Joe Julian <[email protected]> wrote:
> On 05/17/17 02:02, Pranith Kumar Karampuri wrote: > > On Tue, May 16, 2017 at 9:38 PM, Joe Julian <[email protected]> wrote: > >> On 04/13/17 23:50, Pranith Kumar Karampuri wrote: >> >> >> >> On Sat, Apr 8, 2017 at 10:28 AM, Ravishankar N <[email protected]> >> 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? > > > No, that's not comparing like to like and I've rarely had a use case to > which a single-store NFS was the answer. > Exactly. Why is it so bad compared to kNFS? Is there any scope for improvement is the question we are trying to find answer to. If there is everyone wins :-) PS: I may not respond till tomorrow. Will go to sleep now. > > > > >> >> >> 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@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@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@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@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@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@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: [email protected] >>> 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 >>> [email protected]http://lists.gluster.org/mailman/listinfo/gluster-users >>> >>> _______________________________________________ Gluster-users mailing >>> list [email protected] http://lists.gluster.org/mailm >>> an/listinfo/gluster-users >> >> -- >> Pranith >> >> _______________________________________________ >> Gluster-users mailing >> [email protected]http://lists.gluster.org/mailman/listinfo/gluster-users >> >> _______________________________________________ Gluster-users mailing >> list [email protected] http://lists.gluster.org/mailm >> an/listinfo/gluster-users > > -- > Pranith > > -- Pranith
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