samba - Jan 1999 - Shared Memory size

The shared mem size option is set to 102400 by default and change is 
discouraged:

The man page (1.9.18p10) says:

This parameter is only useful when Samba has  been  compiled
	with  FAST_SHARE_MODES.  It specifies the size of the shared
	memory (in bytes) to use between smbd processes. You  should
	never  change  this  parameter  unless  you have studied the
	source and know what you are doing. This parameter  defaults
	to  1024  multiplied by the setting of the maximum number of
	open files in the file local.h in  the  Samba  source  code.
	MAX_OPEN_FILES  is  normally  set  to 100, so this parameter
	defaults to 102400 bytes.

and John Blair's excellent book indicates it is a hacker option.

As far as I can see there is no other documentation on this option.

However I have a server (used for software distribution) to 100+ NT clients 
and it clearly ran out of shared memory eg:

Jan  7 14:55:37 cedar.brunel.ac.uk smbd[27486]: ERROR:set_share_mode shmops->
shm
_alloc fail!
Jan  7 14:55:37 cedar.brunel.ac.uk smbd[27486]: ERROR shm_alloc : alloc of 56 
by
tes failed
Jan  7 14:55:37 cedar.brunel.ac.uk smbd[27486]: ERROR:set_share_mode shmops->
shm
_alloc fail!
Jan  7 14:55:41 cedar.brunel.ac.uk smbd[28154]: PANIC ERROR:del_share_mode 
hash 
bucket 3 empty

Can I just up the amount of shared memory?

Is there any guideline for amount consumed per oplock?

I am running under Solaris 2.5.1 if that helps.

Thanks,

-- 
-----------------------------------------------------------------------------
| Peter Polkinghorne, Computer Centre, Brunel University, Uxbridge, UB8 3PH,|
| Peter.Polkinghorne@brunel.ac.uk   +44 1895 274000 x2561       UK          |
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> In a posting to the Samba list on Jan 13 you stated "Also because of
the
> way shared memory works on Solaris I have to reboot to make the change
> take effect!" 
> 
> Not sure why you have to reboot Solaris. I'm getting ready to do the
> same thing you just did, increase the shared mem maximum for Samba. When
> you changed Samba did you also change /etc/system? I'm curious as to
why
> you needed to do a reboot as opposed to restarting Samba.
> 
> Bob Schell
The problem I faced was that the shared memory segment has a fixed key & did
not go away.  I am unsure if this was because I failed to stop all daemons - 
but I am pretty sure I did.  The the other key thing I did not know about was 
ipcsrm(1) which allows for the removal of shared memory segments - provided 
they have been detached.  I did not change /etc/system.

So yes you are correct, a reboot should not be necessary.[Copying to the list 
to make sure all know about this - YMMV on other Unix versions]

-- 
-----------------------------------------------------------------------------
| Peter Polkinghorne, Computer Centre, Brunel University, Uxbridge, UB8 3PH,|
| Peter.Polkinghorne@brunel.ac.uk   +44 1895 274000 x2561       UK          |
-----------------------------------------------------------------------------