[Samba] File locking problem involving Samba, Clearcase, and
rob.shinn at gmail.com
Fri Feb 6 21:23:42 GMT 2009
On Fri, Feb 6, 2009 at 1:23 PM, Kathy <banshee135 at gmail.com> wrote:
> # first statement is old and may not be obsolete but we still keep it
> just in case
> oplocks = no
> kernel oplocks = no
> level2 oplocks = no
If you have 'oplocks = no', then it doesn't matter what 'kernel oplocks' or
'level2 oplocks' are set to. Samba will ignore them.
However, as shown below, we're seeing oplocks reported and I have no
> idea whether this is normal or not. I asked a Clearcase support guy
> and he did not know (sigh). So hence I'm hoping someone here has some
> experience with this. Again, we ran this same sort of set up before
> with a Solaris Clearcase/Samba server and we didn't see these
> problems. This may not be related to Clearcase at all and simply and
> issue of how file locking is working between RHEL 5.2 and Samba. What
> exactly is a LEVEL_II oplock and why am I seeing these if I have Samba
> oplocks turned off?
level2 oplocks from smb.conf manpage:
Level2, or read-only oplocks allow Windows NT clients that have an oplock on
a file to downgrade from a read-write oplock to a read-only oplock once a
second client opens the file (instead of releasing all oplocks on a second
open, as in traditional, exclusive oplocks). This allows all openers of the
file that support level2 oplocks to cache the file for read-ahead only (ie.
they may not cache writes or lock requests) and increases performance for
many accesses of files that are not commonly written (such as application
if oplocks = no, then the 'level2 oplocks; doesn't do anything.
Note that oplocks parameter should be set per share. Please post the output
of your 'testparm' command.
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