[Samba] Re: How Samba let us down

Bradley W. Langhorst brad at langhorst.com
Wed Oct 23 13:41:11 GMT 2002

On Wed, 2002-10-23 at 04:54, Chris de Vidal wrote:

> You could be right here.  The author in the link above
> indicated that it might be a problem with small RAID 5
> random read/writes.  Know how to see I/Os/sec on
> Linux, by chance?  Bonnie++?  I'm still learning about
> Linux through experience, reading, and asking
> questions (:
iostat is the tool you want here...

> I'm still learning about Linux.. how would a
> user/system/io breakdown be done?  Some flag of ps?
iostat can help you here.
> > Actually, while they can improve performance, they
> > are an inherently less 
> > reliable option than no-oplocks. Even on pure MS
> > networks there are special 
> > cases where they can cause trouble. (it does require
> > other things to go wrong to 
> > trigger them tho).
> So.. it is safe to turn them off?
yes it's safe to turn them off and if you don't have a lot of contention
for files then you should have no performance hit either

> > I generally find level 3 debugs are the lowest level
> > usefull for tracing, but 
> > that enabling them for all processes will massively
> > affect performance - 
> > particularly if your logs go to that raid-5 volume
> > :-)
> Seperate drive for the OS + logs.  I'd heard level 3
> was too slow so I didn't go that high.  I'll take it
> up that high on a client basis using your next advice.
> > I generally selectively enable logs using smbcontrol
> > for particular clients, and 
> > use a level of 3-5.
I second that - turn up the log on troublesome processes to see what's
happening.  The bad news is that you might not be able to get to the
client before the problems are gone...
If performance is really not a problem (as you've mentioned) you could
try cranking the log up to 3

> By chance, do you use ACLs?
i use acls - people like them..
i wouldn't think there'd be a particular performace hit with them

another thing to consider - what is your filesystem on those machines...

i've had bad luck with reiserfs (a while ago though)
and nothing but success with xfs
no experience with ext3
(you'd be nuts to use ext2 on such a large filesystem)

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