[LU-4757] Unable to set upper limit on ost_io threads Created: 12/Mar/14  Updated: 09/Oct/21  Resolved: 09/Oct/21

Status: Resolved
Project: Lustre
Component/s: None
Affects Version/s: Lustre 2.4.2
Fix Version/s: None

Type: Bug Priority: Minor
Reporter: Brett Lee (Inactive) Assignee: WC Triage
Resolution: Won't Fix Votes: 0
Labels: None

Severity: 3
Rank (Obsolete): 13090

 Description   

On an OSS, am unable to configure a persistent throttle the number of ost_io threads. It may be user or doc error, but have tried kernel module settings and a few different conf_param syntax, per section 32.9 of the Lustre manual:

[root@oss0 ~]# lctl get_param ost.OSS.ost_io.threads_max
ost.OSS.ost_io.threads_max=512

[root@oss0 ~]# cat /etc/modprobe.d/lustre.conf
options lnet networks=tcp1(eth3)
options ost oss_num_threads=256

[root@oss0 ~]# lctl conf_param cal.ost.ost_io.threads_max=128
No device found for name MGS: Invalid argument
This command must be run on the MGS.
error: conf_param: No such device

[root@oss0 ~]# lctl conf_param ost.OSS.ost_io.threads_max=128
No device found for name MGS: Invalid argument
This command must be run on the MGS.
error: conf_param: No such device

[root@oss0 ~]# lctl set_param ost.OSS.ost_io.threads_max=128
ost.OSS.ost_io.threads_max=128

[root@oss0 ~]# lctl get_param ost.OSS.ost_io.threads_max
ost.OSS.ost_io.threads_max=128

[root@oss0 ~]# cat /proc/fs/lustre/version
lustre: 2.4.2
kernel: patchless_client
build: 2.4.2-RC2--PRISTINE-2.6.32-358.23.2.el6_lustre.x86_64



 Comments   
Comment by Andreas Dilger [ 14/Mar/14 ]

Did you notice the part of the conf_param "This command must be run on the MGS."? Also, sadly, the device naming for conf_param is different than set_param, you need to check the manual, since I don't know it offhand.

The module parameters definitely should work, however, so this needs further investigation.

Comment by Brett Lee (Inactive) [ 27/Mar/14 ]

Yes, I did see that about conf_param on the MGS, but attributed that to a mistake as it didn't seem logical (looks like the mistake is mine). I have this as an open item to verify the functionality, so will report back once I've checked via the MGS.

Comment by Andreas Dilger [ 09/Oct/21 ]

"lctl conf_param" is deprecated, use "lctl set_param -P" instead.

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