Hi Pranith & Ravi,
A couple of quick questions
We have profile turned on. Are there specific queries we should make
that would help debug our configuration? (The default profile info was
previously sent in
http://lists.gluster.org/pipermail/gluster-users/2017-May/030840.html
but I'm not sure if that is what you were looking for.)
We also started to do a test on serving gluster over NFS. We
rediscovered an issue we previously reported (
http://lists.gluster.org/pipermail/gluster-users/2016-September/028289.html
) in that the NFS mounted version was ignoring the group write
permissions. What specific information would be useful in debugging this?
Thanks
Pat
On 04/14/2017 03:01 AM, Ravishankar N wrote:
On 04/14/2017 12:20 PM, Pranith Kumar Karampuri wrote:
On Sat, Apr 8, 2017 at 10:28 AM, Ravishankar N
<ravishan...@redhat.com <mailto:ravishan...@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?
I have heard anecdotal evidence time and again on the ML and IRC,
which is why I wanted to compare it with NFS numbers on his setup.
Pat,
I see that I am late to the thread, but do you happen to have
"profile info" of the workload?
You can follow
https://gluster.readthedocs.io/en/latest/Administrator%20Guide/Monitoring%20Workload/
to get the information.
Yeah, Let's see if profile info shows up anything interesting.
-Ravi
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:pha...@mit.edu
<mailto:pha...@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
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--
Pranith
--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Pat Haley Email: pha...@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
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