Solaris fssnap and realtime processes

Wednesday, 21. 12. 2005  –  Category: all, vague

fsnap(1M) is most woo-esque for backing up filesystems, in a

  • snapshot filesystem
  • dump filesystem to tape
  • release snapshot
  • check dump

kind of manner.

It does, however, have problems with realtime priority processes. If the executable of such a process resides on the filesystem being snapshotted, things don’t work:
snapshot error: File system could not be write locked  

Quick solution: identify these processes and halt them across the snapshot:

#   priocntl -d -i class RT
REAL TIME PROCESSES:
    PID    RTPRI       TQNTM
    577       0           0       

In this case, pid 577 was xntpd(1M).

Perhaps a better attempt would be to temporarily jigger the priority away from realtime.

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