LinuxQuestions.org
LinuxAnswers - the LQ Linux tutorial section.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices

Reply
 
Search this Thread
Old 11-24-2003, 11:03 PM   #1
BrianK
Senior Member
 
Registered: Mar 2002
Location: Los Angeles, CA
Distribution: Debian, Ubuntu
Posts: 1,334

Rep: Reputation: 51
nfs write == super slow; read == super fast - problem?


brand new boxes running RH9 (downloaded a couple weeks ago, so it should be current) with integrated Intel GigE running on the PRO1000 drivers through a netgear 24-port unmanaged GigE switch (GigE on all ports). The boxes have single platter Hitachi 40GB HD's (8MB buffer, 7200 RPM) and 1GB of PC3200 RAM running dual channel. The FSB is running around 811 MHz with a 2.6 GHz Intel P4.

scp'ing a ~400MB file from one box to another takes about 15 seconds.
nfs reading the file takes about the same time
nfs writing the file takes about 12 minutes.

dd if=/dev/zero of=/mnt/home/testfile bs=16k count=256
takes just over 10 seconds (using the time command to judge)

I've tried changing the read & write block size from 8192 all the way to 32768 (I'm using nfs v2 & 3) - no change.

I've double checked the MTU settings (currently at 1500 on the card and via tracepath)

I've tried changing size of the socket input queue to 256K.

*To note: Every machine on my network is looking at 192.168.0.1 as a DNS server. 192.168.0.1 is not serving up DNS at the moment (new office - haven't setup a DNS server yet). Could this be causing problems? All machines in question have entries in eachother's hosts file.
I've disabled iptables. (didn't think that would make a difference)

Why is my nfs write going so slow?

edit:

/etc/exports on the server side is using the options: bg,noac,no_root_squash,no_subtree_checking,sync

I have five identical machines nfs mounted to one another (using different directories)

Last edited by BrianK; 11-24-2003 at 11:10 PM.
 
Old 11-26-2003, 03:48 AM   #2
BrianK
Senior Member
 
Registered: Mar 2002
Location: Los Angeles, CA
Distribution: Debian, Ubuntu
Posts: 1,334

Original Poster
Rep: Reputation: 51
bump. anyone... anyone.... beuler... beuler?

I really don't know much about nfs - maybe I've overlooked something simple?
 
Old 11-26-2003, 08:14 AM   #3
archangel_617b
Member
 
Registered: Sep 2003
Location: GMT -08:00
Distribution: Ubuntu, RHEL/CentOS, Fedora
Posts: 234

Rep: Reputation: 42
Well you seem to more about the network setup then I do but the one thing I would recommend changing is going from 'sync' to 'async'. From many of the sources I've read, you only need 'sync' if the data is crucial and must be preserved even if the system crashes. Since you're probably using a journaled filesystem (ext3) then data loss even for harddisk failure is fairly low anyhow.

Other then that, no idea. Very strange that you can get scp rw as fast and you get nfs ro.
 
Old 11-28-2003, 05:30 PM   #4
Merlin-TC
LQ Newbie
 
Registered: May 2003
Location: Germany
Distribution: Gentoo
Posts: 16

Rep: Reputation: 0
I am faceing a similiar problem.

I am just running a 100MBit network but my reading perfomance is ok but if I want to write something on the NFS server I have around 60kb/s (no joke).
FTP works like a charm with 10MB/s though.

NFS and Samba are mainly using UDP right?
Could this be the problem? Actually UDP should be slighty faster then.
I am kinda desperate and don't know what to try anymore.
I have a realtek 8169 Gigabit card but it's connected to a 100MBit network and so running only as a 100MBit card.

Any hints or suggestions would be very welcome.
 
Old 08-23-2007, 10:59 PM   #5
cmcginty
LQ Newbie
 
Registered: Feb 2002
Posts: 9

Rep: Reputation: 0
This link might be helpful.

http://www.acc.umu.se/~maswan/linux-netperf.txt
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
k3b - slow read, but fast write bob66 Linux - Software 5 05-13-2005 05:35 PM
For those with the FC4 super slow problem longblock454 Fedora 10 03-30-2005 08:26 AM
Super slow 3D Accel. Zujin Slackware 3 11-25-2004 03:45 AM
my system is super slow zak3 Linux - Hardware 2 01-20-2004 04:42 PM
Making linux super fast! Mwahahaha! Abe_the_Man Linux - Newbie 4 08-16-2003 02:34 PM


All times are GMT -5. The time now is 10:37 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration