NFS really slow (too slow!)

NFS really slow (too slow!)

Post by Eildert Groeneve » Thu, 22 May 1997 04:00:00



The reason for slow clients seem to be know pretty well: apparently the
NFS protocol acknowledges every separate write which bogs down throughput
tremendously when writing short records. In my opinion this is the only but
mayor shortcoming of Linux over commercial unixes like Solaris. We are in
the process of replacing our SUNs by a linux network. However, we are using
applications that use unbuffered writes and are therefore basically useless
in NFS mounted filesystems.
Until this is changed LINUX will be a great platform for standalone
machines but will not function well in a proper network.

--
=========================================
Eildert Groeneveld
Institut fuer Tierzucht und Tierverhalten
Mariensee 31535 Neustadt Germany
Tel: (49)(0)5034 871155
Fax: (49)(0)5034 92579

=========================================

 
 
 

NFS really slow (too slow!)

Post by Klaus Steinberg » Thu, 22 May 1997 04:00:00


|> The reason for slow clients seem to be know pretty well: apparently the
|> NFS protocol acknowledges every separate write which bogs down throughput
|> tremendously when writing short records. In my opinion this is the only but
|> mayor shortcoming of Linux over commercial unixes like Solaris. We are in
|> the process of replacing our SUNs by a linux network. However, we are using
|> applications that use unbuffered writes and are therefore basically useless
|> in NFS mounted filesystems.
|> Until this is changed LINUX will be a great platform for standalone
|> machines but will not function well in a proper network.

Oh Linux does work very well in a networked environment as long as you do not
use SUN servers, which insist on sync write. Any other box including Linux
itself serves better (as long as you don't use that NVRAM options for SUN's).

Of course there are some places in the client and in the server code of Linux
NFS which need enhancements. Olaf Kirch is working on it, he develops an
kernel based server (including long missed file/record locking) as well
as client enhancements. He is also in the first stages of NFS V3 development.

Sincerly,
Klaus

--
Klaus Steinberger               Beschleunigerlabor der TU und LMU Muenchen
Phone: (+49 89)289 14287        Hochschulgelaende, D-85748 Garching, Germany

URL: http://www.bl.physik.tu-muenchen.de/~k2/

 
 
 

NFS really slow (too slow!)

Post by Eildert Groeneve » Fri, 23 May 1997 04:00:00


Klaus is correct, the problem is indeed SOLARIS. Thanx for the pointer!!!!

: |> The reason for slow clients seem to be know pretty well: apparently the
: |> NFS protocol acknowledges every separate write which bogs down throughput
: |> tremendously when writing short records. In my opinion this is the only but
: |> mayor shortcoming of Linux over commercial unixes like Solaris. We are in
: |> the process of replacing our SUNs by a linux network. However, we are using
: |> applications that use unbuffered writes and are therefore basically useless
: |> in NFS mounted filesystems.
: |> Until this is changed LINUX will be a great platform for standalone
: |> machines but will not function well in a proper network.

: Oh Linux does work very well in a networked environment as long as you do not
: use SUN servers, which insist on sync write. Any other box including Linux
: itself serves better (as long as you don't use that NVRAM options for SUN's).

: Of course there are some places in the client and in the server code of Linux
: NFS which need enhancements. Olaf Kirch is working on it, he develops an
: kernel based server (including long missed file/record locking) as well
: as client enhancements. He is also in the first stages of NFS V3 development.

: Sincerly,
: Klaus

: --
: Klaus Steinberger               Beschleunigerlabor der TU und LMU Muenchen
: Phone: (+49 89)289 14287        Hochschulgelaende, D-85748 Garching, Germany

: URL: http://www.bl.physik.tu-muenchen.de/~k2/

--
=========================================
Eildert Groeneveld
Institut fuer Tierzucht und Tierverhalten
Mariensee 31535 Neustadt Germany
Tel: (49)(0)5034 871155
Fax: (49)(0)5034 92579

=========================================

 
 
 

1. HELP: Slow NFS client to server causing Very slow NFS install

My RH 5.2 NFS Install is SO SLOWWW!!

This is taking forever!!  The link speed currently is
284 MB in 17 hours!! or 4.6kbytes/s ~ 46kbps

Why is there such a slow server to client link?

I'm doing this using Lynksys Etherfast 10/100 card on a PII350 desktop
and
a P75 laptop with the PCMCIA version of the Etherfast 10/100.  The
status
LEDs on the cards both indicate that the connections is at 100Mbps, but
the

See below for all of my network config files in /etc.

I believe that with host.conf setup for "order hosts,bind" that I don't
need a
nameserver.  I don't have a local name server setup.  

I have tried modifying some of the parameters below during the
installation,
running exportfs and turning eth0 off and on (using usernet on the
desktop)
DURING THE INSTALLATION (it seems that RH5.2 mounts "hard" during NFS
Install,
ie it is continuing on after I turn eth0 back on) but with no change on
performance.

I did notice when I set the network up before the install that pinging
from
client to server was odd, some packets took 10ms, others took 1000ms in
an
almost every other packet trade off.  The ping from server to client was
on
the order of 10 ms every packet.  Now with the install going on, ping
from
server (desktop) is averaging 350ms with any packet size from 256Bytes
to
8kbytes.  

I have the following setups in exports, host.conf, hosts, hosts.deny,
hosts.allow and resolv.conf:

 cat exports
/mnt/cdrom laptop(ro)  
/home/chris laptop(rw)

cat host.conf
order hosts,bind
multi on

 cat hosts
192.168.0.1     desktop.mylocal.net   desktop
192.168.0.3     laptop.mylocal.net   laptop
127.0.0.1       localhost       loopback

 cat hosts.deny
ALL: ALL
portmap: ALL

 cat hosts.allow
ALL: LOCAL
portmap: 192.168.0.0/255.255.255.0

 cat resolv.conf
domain mylocal.net
#nameserver 140.174.162.14    
#nameserver 140.174.162.10

I have tried resolv.conf with and without commenting out the nameservers
(my
local isp nameservers,) but with no effect.

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