samba - Mar 2000 - problems with samba and Perc/2 RAID

Hi,

	We recently acquired a Dell PowerEdge 4300 with two PIII 500
Xeons and half a gig of RAM, running RedHat 6.1 out of the box.  In
addition, it has a PERC2/SC Single Channel RAID card for six 18GB LVD
SCSI drives.
	The problem is that, while we're not doing anything fancy with
samba, basic file share stuff, the load seems to spike whenever writes
are done.  When doing a large file copy, the load will steadily rise to
about 7 or 8, and then the share stops responding, killing any file
copy taking place.
	It's not the RAID that's causing the problem per se; when I do
a large file copy on the server, the copy works just fine without a
load spike taking place.
 	Has anyone else had this problem before?
	Also, sometimes shares tend to disappear without warning.  For
instance, the /home share will be working fine, and then suddenly
disappear from Windows client access without warning.  Restarting smb
and nmb seems to clear the problem, but it happens again eventually.

	I apologize if this is the wrong place to post this; I'm a
linux / samba newbie, but can't find any reference to this problem on
the web.

Thanks,

John

John (Shiro) saith:
> We recently acquired a Dell PowerEdge 4300 with two PIII 500
> Xeons and half a gig of RAM, running RedHat 6.1 out of the box.  In
> addition, it has a PERC2/SC Single Channel RAID card for six 18GB LVD
> SCSI drives.
> The problem is that, while we're not doing anything fancy with
> samba, basic file share stuff, the load seems to spike whenever writes
> are done.  When doing a large file copy, the load will steadily rise to
> about 7 or 8, and then the share stops responding, killing any file
> copy taking place.
> It's not the RAID that's causing the problem per se; when I do
> a large file copy on the server, the copy works just fine without a
> load spike taking place.
	Ok, somethin's wierd: Samba just does open, read/write, close
	when it's doing i/o. It **should** be indistinguishable from
	a local copy.

	Try a local copy to /dev/null and  a samba copy to /dev/null,
	and see if the samba load leaps up.  If so, it's related to
	the network rather than the disk.

	Run trace/truss/strace on the samba process and email me the
	results: I'll snip out the interesting parts and post them here.
	(But I'm only in town until thursday)

--dave
-- 
David Collier-Brown,  | Always do right. This will gratify some people
185 Ellerslie Ave.,   | and astonish the rest.        -- Mark Twain
Willowdale, Ontario   | //www.oreilly.com/catalog/samba/author.html
Work: (905) 415-2849 Home: (416) 223-8968 Email: davecb@canada.sun.com