samba - Oct 2001 - Very slow performance after installing RAID controllers

Hi all -

I never got an answer last time I posted this, so I'll try again.

I have an old Compaq Proliant 2500R with dual PPro 200 CPUs and a gig of RAM.  I
used to have an external Proliant Storage System F1 array with seven 9.1GB
drives attached to the on-board SCSI controller on the server, and I used
software RAID under Red Hat 7.0.  The performance of Samba (2.0.6, maybe?) was
great - very fast copying files to and from the server over 100MB/s ethernet.

I just installed two Smart-2/P array controllers and an additional F1 external
array, this one with 36GB drives.  This puts one external array on each of the
array controllers.  I also upgraded to Red Hat 7.1.  Now, network performance is
horrible!  a 100 meg file takes 15-20 minutes to copy from the server to a
client PC.

Here's the weird part - when I copy files from one external array to the
other using the cp command at the console, it is very fast (650MB in under two
minutes).  When I copy files within each array, it is also similarly fast.  So,
I don't think it is disk subsystem - I only mention it because I'm
grasping at straws here.

I have tried downloading and compiling Samba 2.2.2.  I have fiddled with
SO_SNDBUF and SO_RCVBUF as well, but it doesn't affect the speed at all.

Anyone have any idea why network performance would tank so badly in these
circumstances?  I really don't want to yank the array controllers, but
I'm about at the end of my rope...

Thanks for any guidance at all.
Thomas Cameron
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I want to apologize - I just re-installed Windows and I forgot to turn off
HTML formatting.  Sorry for sending HTMl to the list in my previous post.

Mea maxima culpa.

Thomas

----- Original Message -----
From: Thomas Cameron
To: samba@lists.samba.org
Sent: Thursday, October 25, 2001 1:40 AM
Subject: Very slow performance after installing RAID controllers


Hi all -

I never got an answer last time I posted this, so I'll try again.

I have an old Compaq Proliant 2500R with dual PPro 200 CPUs and a gig of
RAM.  I used to have an external Proliant Storage System F1 array with seven
9.1GB drives attached to the on-board SCSI controller on the server, and I
used software RAID under Red Hat 7.0.  The performance of Samba (2.0.6,
maybe?) was great - very fast copying files to and from the server over
100MB/s ethernet.

I just installed two Smart-2/P array controllers and an additional F1
external array, this one with 36GB drives.  This puts one external array on
each of the array controllers.  I also upgraded to Red Hat 7.1.  Now,
network performance is horrible!  a 100 meg file takes 15-20 minutes to copy
from the server to a client PC.

Here's the weird part - when I copy files from one external array to the
other using the cp command at the console, it is very fast (650MB in under
two minutes).  When I copy files within each array, it is also similarly
fast.  So, I don't think it is disk subsystem - I only mention it because
I'm grasping at straws here.

I have tried downloading and compiling Samba 2.2.2.  I have fiddled with
SO_SNDBUF and SO_RCVBUF as well, but it doesn't affect the speed at all.

Anyone have any idea why network performance would tank so badly in these
circumstances?  I really don't want to yank the array controllers, but
I'm
about at the end of my rope...

Thanks for any guidance at all.
Thomas Cameron

On Thursday 25 October 2001 02:40, Thomas Cameron wrote:
<SNIP>
> I just installed two Smart-2/P array controllers and an additional F1
> external array, this one with 36GB drives.  This puts one external array on
> each of the array controllers.  I also upgraded to Red Hat 7.1.  Now,
> network performance is horrible!  a 100 meg file takes 15-20 minutes to
> copy from the server to a client PC.
I think you're posting to the wrong list ... you changed HW and OS and
you blame samba for network problems?
> Here's the weird part - when I copy files from one external array to
the
> other using the cp command at the console, it is very fast (650MB in under
> two minutes).  When I copy files within each array, it is also similarly
> fast.  So, I don't think it is disk subsystem - I only mention it
because
> I'm grasping at straws here.
Yes, but if you FTP/scp or do any other kind of _network_ copying (other
than through samba) how does the performance look?  If it looks as crappy
as the samba performance, then you need to look at your network config
before bothering with samba.
> I have tried downloading and compiling Samba 2.2.2.  I have fiddled with
> SO_SNDBUF and SO_RCVBUF as well, but it doesn't affect the speed at
all.
You may be tweaking the wrong knobs.
> Anyone have any idea why network performance would tank so badly in these
> circumstances?  I really don't want to yank the array controllers, but
I'm
> about at the end of my rope...
New hardware that conflicts with your network card?  New OS that with buggy
drivers for your network card?  I think these would be more likely suspects at
this point than samba.
Do some transfer tests with ftp and/or scp or any other network traffic (other
than samba) and see if the performance is up to what you expect.  If it
doesn't
match the crappy samba performance, then you may have a samba problem.
But all network traffic is slow, you'll want to check interrupts, ifconfig
and even
wiring.

-- 
Bill Moran
Potential Technology technical services
(412) 793-4257

Try swapping the NIC to a different PCI Slot
I've had machines where the a specific PCI Slot has failed, you probably
could have a failing slot

Tyler
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Maybe you already checked this, but a duplex mismatch can cause sporadic
network slowness.  (i.e., a card that's running at half duplex while
connected to a switch that's full duplex, or vice versa.)  It'll work
fine
if you ping the machine, or anything small like that, but as soon as you try
to move a lot of data everything goes to pot.  Amazingly enough the
collisions don't always get logged by the OS of the machine at fault when
this happens.

Thanks, Tyler.  It is actually an on-board NIC, so I don't have that option,
but I am going to try to install a second NIC.

Thomas
----- Original Message -----
From: Tyler BIRD
To: archimage@linux-magic.com ; samba@lists.samba.org
Sent: Thursday, October 25, 2001 12:09 PM
Subject: Re: Very slow performance after installing RAID controllers


Try swapping the NIC to a different PCI Slot
I've had machines where the a specific PCI Slot has failed, you probably
could have a failing slot

Tyler

OK, more info.

It looks like I was wrong - ftp, http and scp performance are all fine.
Also, the speed copying from one RAID array to another is good, and copying
data within the RAID array (i.e. cp foo.tar.gz bar.tar.gz) is very fast,
too.

This is definitely a Samba problem.  It's like there's some kind of
disconnect between Samba and the disk subsystem.

Any pointers?

Thomas
> Hi all -
>
> I never got an answer last time I posted this, so I'll try again.
>
> I have an old Compaq Proliant 2500R with dual PPro 200 CPUs and a gig of
> RAM.  I used to have an external Proliant Storage System F1 array with >
seven 9.1GB drives attached to the on-board SCSI controller on the > server,
and I used software RAID under Red Hat 7.0.  The performance of > Samba
(2.0.6, maybe?) was great - very fast copying files to and from > the server
over 100MB/s ethernet.
>
> I just installed two Smart-2/P array controllers and an additional F1 >
external array, this one with 36GB drives.  This puts one external array > on
each of the array controllers.  I also upgraded to Red Hat 7.1.  Now, >
network performance is horrible!  a 100 meg file takes 15-20 minutes to >
copy from the server to a client PC.
>
> Here's the weird part - when I copy files from one external array to
the > other using the cp command at the console, it is very fast (650MB in
> under two minutes).  When I copy files within each array, it is also >
similarly fast.  So, I don't think it is disk subsystem - I only mention
> it because I'm grasping at straws here.
>
> I have tried downloading and compiling Samba 2.2.2.  I have fiddled with
> SO_SNDBUF and SO_RCVBUF as well, but it doesn't affect the speed at
all.
>
> Anyone have any idea why network performance would tank so badly in >
these circumstances?  I really don't want to yank the array controllers,
> but I'm about at the end of my rope...
>
> Thanks for any guidance at all.
> Thomas Cameron