How To
Summary
After shutdown gpfs daemon, lsmod still shows tracedev module there.
The Spectrum Scale functionality is sustained by 3 separated daemons, which are mmfsd, CCR server and mm monitor. It is by design that CCR service daemon will be started after mmfsd daemon shutdown. The CCR service daemon, in turn, hooks tracedev module so that tracedev module is still in use after mmshutdown.
In order to unload tracedev, it needs to shut down mmfsd, CCR service and mm monitor.
Objective
Symptom
1. Three modules are used by mmfsd process:
mmfs26 2642370 3
mmfslinux 804372 20 mmfs26
tracedev 48579 3 mmfs26,mmfslinux
2. After mmshutdown, tracedev still in use by a process, causing manual unload to fail:
# lsmod | grep tracedev
tracedev 48579 1
# rmmod tracedev
rmmod: ERROR: Module tracedev is in use
3. System command lsof indicates that tracedev is still used by the CCR service daemon, mmsdrserv:
#lsof /dev/trace0
mmsdrserv 14905 root 3w CHR 246,0 0t0 387960 /dev/trace0
Solution
It is by design that mmsdrserv will be launched after mmshutdown. Manually killing mmsdrserv, this process will be restarted again by mm monitor. Thus, to unload tracedev, it needs to shut down mmfsd, CCR server and mm monitor server.
1. Shutdown GPFS daemon:
mmshutdown
2. Shutdown mm monitor:
mmsysmoncontrol NOINIT stop
3. Shutdown CCR service:
mmcommon killCcrMonitor
4. unload devtrace
rmmod devtrace
To resume GPFS function:
1. Start gpfs mmfsd daemon:
mmstartup
2. Start CCR service:
mmcommon startCcrMonitor
3. Start mm monitor service:
mmsysmoncontrol NOINIT start
Document Location
Worldwide
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STXKQY","label":"IBM Spectrum Scale"},"Component":"mmfs;devtrace","Platform":[{"code":"PF016","label":"Linux"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}}]
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Document Information
Modified date:
21 June 2022
UID
ibm16118084