Re: Bug 800181: NFSv4 on RHEL 6.2 over six times slower than 5.7

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On 07/11/2012 10:38 AM, m.roth@xxxxxxxxx wrote:
For those with threaded mail tools, after it d/l pop-3 at home, I wound up
forwarding this to myself at work, then back to this account, which is
subscribed to the redhat list.

Subject: Re: Bug 80018: NFSv4 on RHEL 6.2 over six times slower than 5.7
Date: Tue, 10 Jul 2012 21:47:29 -0600
From: Corey Kovacs<corey.kovacs@xxxxxxxxx>

TAM = Technical Account Manager.

I asked about auditing and you asked about selinux auditing. Since when is
selinux auditing? I mean the auditd daemon. It can tax the system severely
if not set up correctly.
/var/log/audit/audit.log
And I *said* I was at home, and couldn't look, but yes, auditd is running.
I asked about your exports file, you give me the format for a generic
exports file. If you didn't notice, i am an RHCA. I think I know what the
general format is.
Yeah, and I'm completely unimpressed with your RHCA. You've come on as
*sure* that it's my fault for misconfiguration, not that we might have
found a bug.
I asked about kerberos, you said you didn't know..  how can you NOT know
if you are using kerberos?

I asked you to give us something to work with. You said "read the damn
bug". I did, it's so fricking vague it's ridiculous.
Vague? Really?
You seem to have very little information/knowledge of your system which
isn't too surprising at this point.
<snip>
On Tue, Jul 10, 2012 at 8:47 PM, mark<m.roth@xxxxxxxxx>  wrote:
<snip>
I'll say it one more time: we found the problem on CentOS. We went to
our test RHEL system. Updated it. Exported a directory *from* the RHEL box
to itself, to /mnt/foo, and ran the test, and got the same results.

In fact, I ran it twice today, updating the kernel in between, and with
6.3, it's taking a consistent 7.5 min, instead of the 6.5 we were
getting with 6.2
<snip>

  Now, all that said and done, here are some questions for you which
might help us figure what would help.
1. What options are present on the mount? (cat /proc/mounts, thinks
like sync can be a problem)
/scratch/foo<same_server>(rw,sync,no_wdelay)

<snip>
  2. What does your /etc/exports config look like on your server node
(cat /etc/exports)
As if I don't know what/how to tell you that? See above.
<snip>
  3. You are using NFSv4, are you using Kerberos with it?
No.
I don't believe we have kerborous set with NFS. We do use it for other
things.


   3.a. If so, what mode are you using for your gss/krb flag? (krb5,
krb5i, krb5p)
4. What's your network speed? Are you sure? (ethtool ethX to make sure)

Gigabit.
<snip>
Do you mean selinux auditing? As I said, doing it on the local drive
takes seconds. Doing it from a 5.x NFS server takes about 1.5 min.
Therefore,
there's nothing that could affect it on the one server.

  7. How many clients are hitting your server and how many nfsd threads
are you running on it?

No other clients. This is a test system.


This is by no means an exhaustive list of things to look at.

Anyway, in order to get any real help, you cannot just shout out, "My
stuff is broke, it's Red Hat's fault, no one will listen to me!"

Give us something to work with.
Maybe you should actually *read* everything I wrote. Screw your I'm an
RHCE, here's a real world test:

> From what I wrote:
1. Is this a) a test system, b) a system in use (prod or dev)?
2. Did it export anything before this test?
3. Is it exporting anything to any other server, or only to the same machine?
4. Did I try unpacking to a local drive?
5. Did I find the problem unpacking to an NFS mounted directory that was
mounted FROM THE SAME MACHINE?

<snip>
           mark

I did a quick test on my CentOS 6.2, and I don't see any slow untar.
Here are the steps I did:

On server:
# uname -a
Linux backup62 2.6.32-220.el6.i686 #1 SMP Tue Dec 6 16:15:40 GMT 2011 i686 i686 i386 GNU/Linux

on my desktop:
# uname -a
Linux centos62 2.6.32-220.el6.i686 #1 SMP Tue Dec 6 16:15:40 GMT 2011 i686 i686 i386 GNU/Linux
# mount -t nfs server-ip:/images /mnt
# time tar xvfz /mnt/hs21.tgz
...
real    0m5.496s
user    0m0.438s
sys    0m0.176s

# cd /mnt
time tar xvfz hs21.tgz
...
real    0m20.634s
user    0m0.414s
sys    0m0.135s

# ll hs21.tgz
-rw-r--r-- 1 root root 43725908 Apr  2  2008 hs21.tgz

Is there anything you can do with the DNS settings on the server side?

Allen

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