cifsiostat not showing rB/s and wB/s

[ipvirg]

Environment:
RHEL 8.3 mounts an SMB 3.1.1 share with MSSQL 2019 database located on the share and active SQL workload(queries and update) running on the share.

Problem:
When running cifsiostat, counters rB/s, wB/s, fc/s, fo/s and fd/s are showing zeros even rops/s and wops/s counters are showing CIFS operations.

"cifsiostat 1" output
Filesystem rB/s wB/s rops/s wops/s fo/s fc/s fd/s
\rhel-smb.io\smb-vol-2 0.00 0.00 33316.00 273.00 0.00 0.00 0.00

Filesystem rB/s wB/s rops/s wops/s fo/s fc/s fd/s
\rhel-smb.io\smb-vol-2 0.00 0.00 32607.00 357.00 0.00 0.00 0.00

Any suggestions on how we display rB/s, wB/s, fc/s, fo/s and fd/s counter stats? Also, is there an option in cifsiostat to show the CIFS latency (just like nfsiostat reporting IOPs and latency)?

[sysstat]

Could it be that SMB 3 statistics file's format has changed from previous versions?
Could you please copy/paste the contents of your /proc/fs/cifs/Stats file so that I can check that?

[ipvirg]

Can see bytes read and written in /proc/fs/cifs/Stats

Resources in use
CIFS Session: 1
Share (unique mount targets): 2
SMB Request/Response Buffer: 1 Pool size: 5
SMB Small Req/Resp Buffer: 1 Pool size: 30
Operations (MIDs): 19

0 session 0 share reconnects
Total vfs operations: 25281549 maximum at one time: 22

Max requests in flight: 126

1. \rhel-smb.io\smb-vol-2
   SMBs: 910971924
   Bytes read: 4587067092992 Bytes written: 1478032777216
   Open files: 2 total (local), 2 open on server
   TreeConnects: 1 total 0 failed
   TreeDisconnects: 0 total 0 failed
   Creates: 38130 total 0 failed
   Closes: 38128 total 0 failed
   Flushes: 1165118 total 0 failed
   Reads: 587309930 total 0 failed
   Writes: 322382519 total 0 failed
   Locks: 0 total 0 failed
   IOCTLs: 1 total 0 failed
   QueryDirectories: 14 total 0 failed
   ChangeNotifies: 0 total 0 failed
   QueryInfos: 38084 total 0 failed
   SetInfos: 0 total 0 failed
   OplockBreaks: 0 sent 0 failed

[sysstat]

The format of this file is that expected by cifsiostat.
I used it for my own tests but was unable to reproduce your problem.

[ipvirg]

Mounted the same SMB 3.1.1 share to Ubuntu 20.04/kernel 5.8 and confirmed can see throughput rate stats

Filesystem rB/s wB/s rops/s wops/s fo/s fc/s fd/s
\rhel-smb.io\smb-vol-2 0.00 695795712.00 0.00 9840.00 0.00 0.00 0.00

Filesystem rB/s wB/s rops/s wops/s fo/s fc/s fd/s
\rhel-smb.io\smb-vol-2 0.00 304939008.00 0.00 4210.00 0.00 0.00 0.00

Could it be RHE8.3/kernel 4.18 and cifsiostat defect?

[sysstat]

I don't know, but anyway it seems quite unlikely that your problem is a cifsiostat bug.

[ipvirg]

BTW, is there a roadmap on adding cifs latency on cifsiostat?

[sysstat]

The kernel should provide the needed counters first so that latency can be calculated. And AFAIK these counters don't exist.

[ipvirg]

thanks @sysstat