Hi,
I'm from netapp, but what I can say for you, a netapp is a dedicated box for this kind
of usage (high load)
if you have any questions don't hesitate
Thx
Fab.
-----Original Message-----
From: John White [mailto:[EMAIL PROTECTED]]
Sent: Thursday, May 24, 2001 12:49 AM
To: [EMAIL PROTECTED]
Subject: Re: High Availability, High Volume and NFS
On Wed, May 23, 2001 at 01:40:13PM -0500, Duane Schaub wrote:
> We have tried a Redhat6.1 backend on the NFS with Redhat 6.1 NFS clients.
Others may point out that an observed weakness of the stock linux kernel
from RH 6.1 has been shown to have weak NFS performance when compared to
some of the BSD O/S family.
If you feel comfortable recompiling your kernel, check out
http://nfs.sourceforge.net/
> The result was that the qmail machines were BARELY able to keep up. If
> there were any pauses on the NFS server, the POP sessions would build to
> 50-60 very quickly with qmail crashing at about 300 sessions. Once qmail
> exceeded about 70 sessions, it was beyond the point of return and would not
> recover.
Have you thought about the stopgap measure of throttling down on the
number of concurrent pop3 sessions each machine is allowed? Say you
want to cap it at 50 total. Just use 50/n, where n is the number of
client machines, as the max concurrency for tcpserver (-c). You can
increase the client backlog so all the clients see is a pause (-b).
http://cr.yp.to/ucspi-tcp/tcpserver.html
> The NFS server was nothing special (P350/IDE 256Mb RAM). We also tried a
> Dell 2300 (Dual 400/RAID5) NT server running Intergraph NFS.... But the
> performance was abysmal! Performing an ls in a user/new directory took 21
> seconds for a response.
It will be tempting to throw more hardware at the problem. Depends on
your budget. Right now, I like the the new DDR RAM chipsets for Athlon
processors. I like the idea of 3ware hardware IDE RAID which looks like
a SCSI controller to the system.
Balance the bugetary requirements of upgrading your hardware (without
knowing what the effect will be) vs. changing your O/S (with some
benchmarking already in hand).
Oh, check this out:
http://innominate.org/%7Etgr/projects/tuning/
Check out slide 37 for relevant conclusions, but the entire presentation
is interesting.
> I think NFS would work, but I don't really want a Netapp F5 ($50,000). What
> NFS experiences are out there?
I've read repeated positive reviews with a netapp, but I still would explore
FreeBSD performance first.
John White
