Shenyue Chen
2023-Mar-09 17:15 UTC
[Samba] CIFS client mounts meta ops 30 times slow than server
Hi Samba users,
We would like to use samba for re-exporting our other distributed file
system (BeeGFS). However, we found that the meta data operations are very
slow (dir stat, removal etc.). On SMB client the performance is more than
30x slow than on the SMB server. We would expect some slowness but this is
too big a drop.
This is the result on CIFS client
$ sudo mdtest -b 10 -I 10 -L -z 2
mdtest-3.3.0 was launched with 1 total task(s) on 1 node(s)
Command line used: mdtest '-b' '10' '-I' '10'
'-L' '-z' '2'
FS: 1341.0 TiB Used FS: 53.8% Inodes: 0.0 Mi Used Inodes: -nan%
Nodemap: 1
1 tasks, 1000 files/directories
SUMMARY rate: (of 1 iterations)
Operation Max Min Mean
Std Dev
--------- --- --- ----
-------
Directory creation : 8.431 8.431
8.431 0.000
Directory stat : 34.470 34.470
34.470 0.000
Directory removal : 11.401 11.401
11.401 0.000
File creation : 15.151 15.151
15.151 0.000
File stat : 26.313 26.313
26.313 0.000
File read : 11.206 11.206
11.206 0.000
File removal : 10.526 10.526
10.526 0.000
Tree creation : 9.121 9.121
9.121 0.000
Tree removal : 15.190 15.190
15.190 0.000
-- finished at 02/17/2023 10:11:41 --
And this is the result of the same folder on SMB server.
$ mdtest -b 10 -I 10 -L -z 2 -- started at 02/17/2023 10:26:11 --
mdtest-3.3.0 was launched with 1 total task(s) on 1 node(s) Command line
used: mdtest '-b' '10' '-I' '10' '-L'
'-z' '2' FS: 1341.0 TiB Used FS:
54.0% Inodes: 0.0 Mi Used Inodes: -nan% Nodemap: 1 1 tasks, 1000
files/directories SUMMARY rate: (of 1 iterations) Operation Max Min Mean
Std Dev --------- --- --- ---- ------- Directory creation : 290.328 290.328
290.328 0.000 Directory stat : 702.193 702.193 702.193 0.000 Directory
removal : 343.934 343.934 343.934 0.000 File creation : 330.556 330.556
330.556 0.000 File stat : 1368.871 1368.871 1368.871 0.000 File read :
519.276 519.276 519.276 0.000 File removal : 454.345 454.345 454.345 0.000
Tree creation : 314.333 314.333 314.333 0.000 Tree removal : 382.234
382.234 382.234 0.000 -- finished at 02/17/2023 10:26:28 --
Additionally, it seems our client does not have any kind of cache
available. I've tried many options:
- cache=loose
- actimeo=3600
- nostrictsync
- noperm
- fsc
- etc....
But none of the seems to have an impact.
Our work load consists of mainly large number of small files.
I know there many possible factors going on here. So I'm wondering if there
is any way we could profile/trace this to tune the performance.
Thanks!
Info:
Client linux kernel version: Ubuntu 22.04 5.15.0-60-generic
Server SMB version: 4.15.13+dfsg-0ubuntu1
Mount options: <path> type cifs
(rw,relatime,vers=3.1.1,cache=strict,username=elvis_chen,uid=0,noforceuid,gid=0,noforcegid,addr=<ip>,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=60,actimeo=1)
Jeremy Allison
2023-Mar-09 17:32 UTC
[Samba] CIFS client mounts meta ops 30 times slow than server
On Fri, Mar 10, 2023 at 01:15:41AM +0800, Shenyue Chen via samba wrote:>Hi Samba users, > >We would like to use samba for re-exporting our other distributed file >system (BeeGFS). However, we found that the meta data operations are very >slow (dir stat, removal etc.). On SMB client the performance is more than >30x slow than on the SMB server. We would expect some slowness but this is >too big a drop. > >This is the result on CIFS client > >$ sudo mdtest -b 10 -I 10 -L -z 2 > >mdtest-3.3.0 was launched with 1 total task(s) on 1 node(s) >Command line used: mdtest '-b' '10' '-I' '10' '-L' '-z' '2' >FS: 1341.0 TiB Used FS: 53.8% Inodes: 0.0 Mi Used Inodes: -nan%Can you be a little clearer on your setup please ? I'm assuming you are mounting the BeeGFS filesystem on the Samba server, and then re-exporting that via Samba to the Linux cifs client. Is that the case ?
Ralph Boehme
2023-Mar-09 17:57 UTC
[Samba] CIFS client mounts meta ops 30 times slow than server
On 3/9/23 18:15, Shenyue Chen via samba wrote:> Server SMB version: 4.15.13+dfsg-0ubuntu1- 30 times slower is actually not that bad for metadata heavy workloads - please use Samba 4.18, that has considerable improved metadata performance - research whether beegfs supports file case lookup that could be used to implement a beegfs specific VFS module (there isn't one yet, but we have VFS modules for other filesystems that support this eg gpfs and glusterfs) Cheers! -slow -- Ralph Boehme, Samba Team https://samba.org/ SerNet Samba Team Lead https://sernet.de/en/team-samba SAMBA+ Samba packages https://samba.plus/ -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature Type: application/pgp-signature Size: 840 bytes Desc: OpenPGP digital signature URL: <http://lists.samba.org/pipermail/samba/attachments/20230309/0cc682a7/OpenPGP_signature.sig>
Shenyue Chen
2023-Mar-09 18:16 UTC
[Samba] CIFS client mounts meta ops 30 times slow than server
Also from my observation, based on network packets and time measurements, it seems the CIFS clients haven't done any sort of cache. For example, doing a "ls" for 5 times on the same folder within a short period of time. The network packet sizes are almost equal every time and the time it takes is similar. Isn't there supposed to be some page cache or dentry cache that could accelerate this, under the loose cache policy? Or is this the expected behavior? Shenyue Chen <chensy1996 at gmail.com> ?2023?3?10??? 01:15???> Hi Samba users, > > We would like to use samba for re-exporting our other distributed file > system (BeeGFS). However, we found that the meta data operations are very > slow (dir stat, removal etc.). On SMB client the performance is more than > 30x slow than on the SMB server. We would expect some slowness but this is > too big a drop. > > This is the result on CIFS client > > $ sudo mdtest -b 10 -I 10 -L -z 2 > > mdtest-3.3.0 was launched with 1 total task(s) on 1 node(s) > Command line used: mdtest '-b' '10' '-I' '10' '-L' '-z' '2' > FS: 1341.0 TiB Used FS: 53.8% Inodes: 0.0 Mi Used Inodes: -nan% > > Nodemap: 1 > 1 tasks, 1000 files/directories > > SUMMARY rate: (of 1 iterations) > Operation Max Min Mean Std Dev > --------- --- --- ---- ------- > Directory creation : 8.431 8.431 8.431 0.000 > Directory stat : 34.470 34.470 34.470 0.000 > Directory removal : 11.401 11.401 11.401 0.000 > File creation : 15.151 15.151 15.151 0.000 > File stat : 26.313 26.313 26.313 0.000 > File read : 11.206 11.206 11.206 0.000 > File removal : 10.526 10.526 10.526 0.000 > Tree creation : 9.121 9.121 9.121 0.000 > Tree removal : 15.190 15.190 15.190 0.000 > -- finished at 02/17/2023 10:11:41 -- > > And this is the result of the same folder on SMB server. > > $ mdtest -b 10 -I 10 -L -z 2 -- started at 02/17/2023 10:26:11 -- > mdtest-3.3.0 was launched with 1 total task(s) on 1 node(s) Command line > used: mdtest '-b' '10' '-I' '10' '-L' '-z' '2' FS: 1341.0 TiB Used FS: > 54.0% Inodes: 0.0 Mi Used Inodes: -nan% Nodemap: 1 1 tasks, 1000 > files/directories SUMMARY rate: (of 1 iterations) Operation Max Min Mean > Std Dev --------- --- --- ---- ------- Directory creation : 290.328 290.328 > 290.328 0.000 Directory stat : 702.193 702.193 702.193 0.000 Directory > removal : 343.934 343.934 343.934 0.000 File creation : 330.556 330.556 > 330.556 0.000 File stat : 1368.871 1368.871 1368.871 0.000 File read : > 519.276 519.276 519.276 0.000 File removal : 454.345 454.345 454.345 0.000 > Tree creation : 314.333 314.333 314.333 0.000 Tree removal : 382.234 > 382.234 382.234 0.000 -- finished at 02/17/2023 10:26:28 -- > > Additionally, it seems our client does not have any kind of cache > available. I've tried many options: > > - cache=loose > - actimeo=3600 > - nostrictsync > - noperm > - fsc > - etc.... > > But none of the seems to have an impact. > > Our work load consists of mainly large number of small files. > > I know there many possible factors going on here. So I'm wondering if > there is any way we could profile/trace this to tune the performance. > > > Thanks! > > Info: > > Client linux kernel version: Ubuntu 22.04 5.15.0-60-generic > Server SMB version: 4.15.13+dfsg-0ubuntu1 > Mount options: <path> type cifs > (rw,relatime,vers=3.1.1,cache=strict,username=elvis_chen,uid=0,noforceuid,gid=0,noforcegid,addr=<ip>,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=60,actimeo=1) >