Hi Pranith,
Not entirely sure (this isn't my area of expertise). I'll run your
answer by some other people who are more familiar with this.
I am also uncertain about how to interpret the results when we also add
the dd tests writing to the /home area (no gluster, still on the same
machine)
* dd test without oflag=sync (rough average of multiple tests)
o gluster w/ fuse mount : 570 Mb/s
o gluster w/ nfs mount: 390 Mb/s
o nfs (no gluster): 1.2 Gb/s
* dd test with oflag=sync (rough average of multiple tests)
o gluster w/ fuse mount: 5 Mb/s
o gluster w/ nfs mount: 200 Mb/s
o nfs (no gluster): 20 Mb/s
Given that the non-gluster area is a RAID-6 of 4 disks while each brick
of the gluster area is a RAID-6 of 32 disks, I would naively expect the
writes to the gluster area to be roughly 8x faster than to the non-gluster.
I still think we have a speed issue, I can't tell if fuse vs nfs is part
of the problem. Was there anything useful in the profiles?
Pat
On 05/10/2017 12:15 PM, Pranith Kumar Karampuri wrote:
Okay good. At least this validates my doubts. Handling O_SYNC in
gluster NFS and fuse is a bit different.
When application opens a file with O_SYNC on fuse mount then each
write syscall has to be written to disk as part of the syscall where
as in case of NFS, there is no concept of open. NFS performs write
though a handle saying it needs to be a synchronous write, so write()
syscall is performed first then it performs fsync(). so an write on an
fd with O_SYNC becomes write+fsync. I am suspecting that when multiple
threads do this write+fsync() operation on the same file, multiple
writes are batched together to be written do disk so the throughput on
the disk is increasing is my guess.
Does it answer your doubts?
On Wed, May 10, 2017 at 9:35 PM, Pat Haley <[email protected]
<mailto:[email protected]>> wrote:
Without the oflag=sync and only a single test of each, the FUSE is
going faster than NFS:
FUSE:
mseas-data2(dri_nascar)% dd if=/dev/zero count=4096 bs=1048576
of=zeros.txt conv=sync
4096+0 records in
4096+0 records out
4294967296 bytes (4.3 GB) copied, 7.46961 s, 575 MB/s
NFS
mseas-data2(HYCOM)% dd if=/dev/zero count=4096 bs=1048576
of=zeros.txt conv=sync
4096+0 records in
4096+0 records out
4294967296 bytes (4.3 GB) copied, 11.4264 s, 376 MB/s
On 05/10/2017 11:53 AM, Pranith Kumar Karampuri wrote:
Could you let me know the speed without oflag=sync on both the
mounts? No need to collect profiles.
On Wed, May 10, 2017 at 9:17 PM, Pat Haley <[email protected]
<mailto:[email protected]>> wrote:
Here is what I see now:
[root@mseas-data2 ~]# gluster volume info
Volume Name: data-volume
Type: Distribute
Volume ID: c162161e-2a2d-4dac-b015-f31fd89ceb18
Status: Started
Number of Bricks: 2
Transport-type: tcp
Bricks:
Brick1: mseas-data2:/mnt/brick1
Brick2: mseas-data2:/mnt/brick2
Options Reconfigured:
diagnostics.count-fop-hits: on
diagnostics.latency-measurement: on
nfs.exports-auth-enable: on
diagnostics.brick-sys-log-level: WARNING
performance.readdir-ahead: on
nfs.disable: on
nfs.export-volumes: off
On 05/10/2017 11:44 AM, Pranith Kumar Karampuri wrote:
Is this the volume info you have?
>/[root at mseas-data2
<http://www.gluster.org/mailman/listinfo/gluster-users> ~]#
gluster volume info />//>/Volume Name: data-volume />/Type: Distribute />/Volume ID:
c162161e-2a2d-4dac-b015-f31fd89ceb18 />/Status: Started />/Number of Bricks: 2 />/Transport-type: tcp
/>/Bricks: />/Brick1: mseas-data2:/mnt/brick1 />/Brick2: mseas-data2:/mnt/brick2 />/Options Reconfigured:
/>/performance.readdir-ahead: on />/nfs.disable: on />/nfs.export-volumes: off /
I copied this from old thread from 2016. This is distribute
volume. Did you change any of the options in between?
--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Pat Haley Email:[email protected]
<mailto:[email protected]>
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
--
Pranith
--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Pat Haley Email:[email protected]
<mailto:[email protected]>
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
--
Pranith
--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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
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