Very Slow NFS access

2007-12-25 11:20:00

The problem I have experienced was with forcing the HME interfaces to

100Mb/s Full Duplex. This was also suggested by most of the responses I

received. This fortunately happened to be the very next item on my list as

I was regressing my steps one-by-one and testing.

I received the following set of responses, all of which may be applicable

for other people even if not all was applicable for me. Thank you all for

assisting me with so little information:

Joe Flechter:

My first inclination would be to check for a duplex mismatch on the

ethernet

interface.

If you've manually fixed the speed at the server end the switch may not

have

followed

suit. The quick and gross way to fix this is to set the speed on the server

then unplug the cable, wait about 10 seconds then plug it back in again.

This will "encourage" your switch to

use 100MbFD. Better still if you have management software on your switch

then set both ends of the link.

Michael Arndt

Try mounting with so called hard mounts if not done already

Seems to me that your measures slowed down tcp Performance

so after some timeout a retry is startet, to get nfs data

if not yet ready the access time grows by some exponentially

working algorithms. If you mount hard, the NFS Client will wait ...

Somewhat strongly oversimplified, but seems youre in a hurrry for long

explanations

Justin Clift

Did you alter the /etc/services file?

I would guess that your problem is in one of the services in

/etc/inetd.conf. I can't think of any other network layer settings which

would affect NFS, unless you are running in a NIS+ environment and turned

off rpc. (bad thing to do).

A quick guess would be to re-enable ALL the services in /etc/inetd.conf (I

know most of these are redundant), paying careful attention to the rpc

ones,

then restart inetd (don't forget this!). IF that works, then disable them

one at a time, when you have time to.

Tom Davidson

 If you use cisco catalyst like I do, I would suspect a speed/duplex

auto negotiation problem. On SGI's, SUN's and NT boxes I've seen the

negotiations to a cisco switch end up screwed up. If you manaually force

the speed and or duplex on the switch, the computer may not change. Or

if you force it on the computer the switch may not negotiate properly.

Sometimes reboots still will not fix the problem if you have manually

set the speed and or duplex in either device. I've usually have to look

at the computers and see what they say they negotiated and then look at

the switch with the show ports command. When a machine has horrible

throughput, this is my first suspect. The computer will work okay on

small networking stuff, but when you try to move a file any bigger than

a meg, then you will see that is seems to take forever and you will get

errors. Make sure the switch and computer say the same duplex and speed.

You can try forcing and rebooting, but sometimes you have to force the

computer and switch to a setting and check to see if you can ftp a 1meg

file fast. If not, the settings are most likely mismatched. On SGI's, I

don't believe you can force the speed and duplex. The models I have

worked with didn't have divers that supported that. I could only see

what the sgi said it negotiated by #ifconfig -av. For the version of

solaris you may have to read the ifconfig man page to see what flags you

can pass to ifconfig to see the link information. Once the link

information is the same for a machine and it's particular port on the

switch, it should transfer a 1meg file in a flash, of course that's

assuming you network isn't dog slow already.

 I hope this information may help you. I can't imagine hardening a

machine will kill network speed. I do see you said you forced the speed

and duplex, which I believe is your problem.

Michael Maciolek

Hopefully you've solved this problem by now...

I'd focus on your network switches. If they autonegotiate, while

the Suns are forced to 100M/full, it's quite possible that you

have a negotiation failure and the switches are trying to talk

100/half.

That would readily account for the poor performance. I've seen

this with Cisco switches mixed with Suns, and I *always* force

the Cisco to 100/Full whenever I force the Sun's settings.

Matt Palmieri

Make sure your portmapper is still running. I think it starts out of a

script in /etc/rc2.d

Michael Hill

The first thing I suspect in cases of network slowdown is name

resolution. Did the hardening possibly alter /etc/nsswitch.conf ?

Theodore Tickell

I've not done anything like that with an e10k in multiple domains, but I

have had two sparcs side by side with a similar problem.

In my case it turned out that when I forced the interface to 100full, the

switch (in this case a catylyst - I ws surprised) stopped sensing

right. That in combination wiht my tcp/ip customizations caused havoc on

the box that i had 'finished' setting up. I was using an qfe card, by the

by, and everything else was pretty standard for a web server tuning. I

got okay performance reversing the tunings, but the big gain was obviously

reseting the interface - then the tunings helped.

Casper Dik

What type of switches do you use?

My experience is that certain switches will fallback to 100Mbps half-duplex

when Sun's are forced to 100Mbs full (forced means no negotiation;)

Try using auto negotiation instead.

Kris

Verify that you have auto negotiation off and force full-duplex!

* Set auto-negotiation to full force 100 on quad fast ethernet 0

set qfe:qfe_adv_autoneg_cap=0

set qfe:qfe_adv_100T4_cap=0

set qfe:qfe_adv_100fdx_cap=1

set qfe:qfe_adv_100hdx_cap=0

set qfe:qfe_adv_10fdx_cap=0

set qfe:qfe_adv_10hdx_cap=0

If you are using hme then replace the variable.

The settings which I did Use, and which I removed in order to solve the

problem, are:

* Ethernet - Force Full duplex and Auto Negotiate off

set hme:hme_adv_autoneg_cap=0

set hme:hme_adv_100T4_cap=0

set hme:hme_adv_100fdx_cap=1

set hme:hme_adv_100hdx_cap=0

set hme:hme_adv_10fdx_cap=0

set hme:hme_adv_10hdx_cap=0

* End of Ethernet mode settings

Finally, I have not yet tried to re-implement these settings.

Unfortunately because of work load this will have to wait until After these

domains have been productionalised and then will need to pass through

change control.

Johan Hartzenberg/GIS/CSC

02/10/2000 12:46 PM

Sent by: Johannes J Hartzenberg/GIS/CSC

To: sun-managers@codeprof.ececs.uc.edu

cc:

Subject: Very Slow NFS access

Hi,

I have just set up 4 domains on E10K. On 2 of these I performed a

"security hardening" and a set of customization steps.

The security hardining includes turning on TCP/IP logging, STRONG TCP=2,

process auditing, etc. I also stopped almost all the redundant and

obsolete services from /etc/inetd.conf The customization includes a horde

of steps, including forcing network ports to 100Mbps and Full Duplex.

I mention what looks to me like the most prominent changes made to

Networking setup.

Now I am busy reversing the steps I heve performed 2 or 3 at a time. On

those domains where I have not performed the hardening and customizing, I

get approx 1200Kb/s when copying CD from NFS share. On those where I have

performed the customization I get terrible speed and the cp -r command

starts to give errors like

NFS time out "still trying"

(This is not the correct error, sue me, I am in a hurry)

Does anybody KNOW what is causing this and can save me many many hours

worth of un-doing changes?

Thanx for your urgent responses, the Dba's are yelling at me because their

new domains is not available at the promised time

  _Johan

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