slow NFS with Linux server

slow NFS with Linux server

Post by Silverstei » Tue, 13 Apr 1999 04:00:00



We have a 4.3.1.0 AIX system which is the client NFS system.
We're using a Linux system for the nfs server (not sure which version of
linux but I think 2.0.X).  It's running NFS 2.

When we do a "cp -r /home/andys/dir1 /scr"  this never completes.  It
starts and copies some files, but then hangs.  /home is nfs mounted.
/scr is local.

If we do the same from /scr to /scr it completes rather quickly.

Also, periodically the display locks up.  When it frees up, a Motif
dialog appears with "Cannot access /home/andys".  This is also on the
nfs mounted partition.

Anyone have any ideas as to why this is happening?
How can we fix this?

Herc

 
 
 

slow NFS with Linux server

Post by Peter Samuels » Sat, 17 Apr 1999 04:00:00



Quote:> We have a 4.3.1.0 AIX system which is the client NFS system.  We're
> using a Linux system for the nfs server (not sure which version of
> linux but I think 2.0.X).  It's running NFS 2.

Linux is very good at a lot of things -- but traditionally its NFS
server has been a weak spot.  [This is hearsay since I have never used
Linux for NFS servers.]  It also has a history of sometimes tickling
bugs in other operating systems' NFS clients -- Solaris 2.6 is the
latest victim on that front....

I *believe* the most solid known NFS server implementation for Linux is
H.J. Lu's newest release of knfsd -- a patch to Linux 2.2.5.  I realize
that upgrading a server from Linux 2.0.x to 2.2.5 is a non-trivial
undertaking, but it is an option worth thinking about (especially if
you have a spare box to use for testing).  Also, reports you may
have heard about the various Linux 2.2.x glitches are most likely
outdated -- 2.2.5 seems to have ironed out almost all of them.  Anyway,
see last week's announcement on Linux Weekly News:

  http://lwn.net/1999/0415/a/knfsd.html

Note also that this version of nfsd still doesn't do NFSv3.  HTH.

--
Peter Samuelson
<sampo.creighton.edu!psamuels>

 
 
 

slow NFS with Linux server

Post by John R. Campbe » Sun, 18 Apr 1999 04:00:00




>> We have a 4.3.1.0 AIX system which is the client NFS system.  We're
>> using a Linux system for the nfs server (not sure which version of
>> linux but I think 2.0.X).  It's running NFS 2.

>Linux is very good at a lot of things -- but traditionally its NFS
>server has been a weak spot.  [This is hearsay since I have never used
>Linux for NFS servers.]  It also has a history of sometimes tickling
>bugs in other operating systems' NFS clients -- Solaris 2.6 is the
>latest victim on that front....

        I'm a Linux enthusiastm but a lot depends upon the network
        interface;  If you are using Token Ring, well, check for
        newer drivers.  If on EtherNet, well, that comment was
        worth less than you paid for it...              :-)

        I've had good luck using NFS on Linux on EtherNet, but
        I've never had enough of a system hammering it.  As it
        is, having an AIX system access files on a PC doesn't
        strike me as that wonderful an idea.  The AIX box should
        have that kind of job-  it has LVM+JFS, which is a heck of
        a lot easier to manage (and, after a class on AIX performance
        manglement, to tune).  Besides, even with a major clock rate
        on a Pentium II, the PC architecture itself is working
        against you.

        OK, so you're using a linux box to deliver files since you
        need more disk space and you don't want to buy/upgrade
        drives from IBM.  Right?

        Have you checked to see that you're actually tuned for
        NFS operations?  (biod/nfsdcounts, etc)  Your Linux
        server may need more nfsd daemons to run to make an
        effort to keep up w/ the RS/6000 (I hope you've tuned
        the Linux box in other areas, like dropping various
        daemons...).  As I said before, though, you really need
        to be running ethernet or a newer T/R driver...

        BTW, the performance class is Q1128;  I just finished it
        today.  Cool stuff.  It's also good for folks who do
        applications, too, though you still need some systems
        knowledge.

--

 - As a SysAdmin, yes, I CAN read your e-mail, but I DON'T get that bored!
   Disclaimer:  All opinions expressed are those of John Campbell alone and
                do not reflect the opinions of his employer(s) or lackeys
                thereof.  Anyone who says differently is itching for a fight!

 
 
 

slow NFS with Linux server

Post by Walter Harm » Sun, 18 Apr 1999 04:00:00


        we run LINUX as a NFS server for pictures, i never noticed
        any problems with that. the connection is a 10Mbit ethernet.

        walter

--
-----
"Well, Ivan, you're the one in the navigator's seat.  What are you doing?"
"Sir, I am instructed to keep this seat warm until Chekov returns."
-----

 
 
 

slow NFS with Linux server

Post by Peter S. Shenki » Sun, 18 Apr 1999 04:00:00


Hi,

I received a useful response by email.

For a LINUX server, AIX 4.3.x client, on the AIX side, use UDP rather than
TCP/IP and specify vers=nfs2.  This seems to work.  We're also running 10 Mb
ethernet.

    -P.


Quote:> we run LINUX as a NFS server for pictures, i never noticed
> any problems with that. the connection is a 10Mbit ethernet.

> walter

> --
> -----
> "Well, Ivan, you're the one in the navigator's seat.  What are you doing?"
> "Sir, I am instructed to keep this seat warm until Chekov returns."
> -----

 
 
 

slow NFS with Linux server

Post by Karl Heye » Tue, 20 Apr 1999 04:00:00



> We have a 4.3.1.0 AIX system which is the client NFS system.
> We're using a Linux system for the nfs server (not sure which version of
> linux but I think 2.0.X).  It's running NFS 2.

> When we do a "cp -r /home/andys/dir1 /scr"  this never completes.  It
> starts and copies some files, but then hangs.  /home is nfs mounted.
> /scr is local.

.....

linux 2.0 nfsd  is a userspace program so it has issues with context
switching.
also what is the r/wsize value of the client.  Note that NFS 2 spec stated
that
all writes need to be committed before return. This kills the buffering. The

newer 2.2 kernel has a another implementation of nfsd which is tried to the
kernel. This allows for async writes which is allowed in NFS V3 and I
believe
that NFS V3 compatibility is almost there.

For 2.0 The best you can do is imcrease the blocksizes if you need to. Known

problem against solaris (8K reads/writes).

for 2.2 use the new kernel-based NFS.

karl

 
 
 

slow NFS with Linux server

Post by Werner Kliewe » Tue, 20 Apr 1999 04:00:00


We are still running AIX 4.2.1, so  I am curious about these changes. Can you
specify UDP on a per mount basis or is it the entire NFS client side that has
to be switched? If global, where is this done? I assume if it is specific to
each connection there must be some new options in SMIT?

Same question about vers=nfs2.

Do not use linux as a primary NFS server, but we run NFS mounts back and forth
between all our systems. Almost all systems, including our linux boxes are
both client and server.


> For a LINUX server, AIX 4.3.x client, on the AIX side, use UDP rather than
> TCP/IP and specify vers=nfs2.  This seems to work.  We're also running 10 Mb
> ethernet.

Werner Kliewer
Manitoba Public Insurance
 
 
 

slow NFS with Linux server

Post by David Marti » Wed, 21 Apr 1999 04:00:00


These options are set at the client side on a per mount basis. Set
options with the mount command switch -o vers=nfs2,proto=tcp
By default nfs uses udp.

David Martin


> We are still running AIX 4.2.1, so  I am curious about these changes. Can you
> specify UDP on a per mount basis or is it the entire NFS client side that has
> to be switched? If global, where is this done? I assume if it is specific to
> each connection there must be some new options in SMIT?

> Same question about vers=nfs2.

> Do not use linux as a primary NFS server, but we run NFS mounts back and forth
> between all our systems. Almost all systems, including our linux boxes are
> both client and server.


> > For a LINUX server, AIX 4.3.x client, on the AIX side, use UDP rather than
> > TCP/IP and specify vers=nfs2.  This seems to work.  We're also running 10 Mb
> > ethernet.

> Werner Kliewer
> Manitoba Public Insurance

--

Bureau of Meteorology, Melbourne, Australia,
Planet Earth, Sol Solar System, Milky Way, Only Known Universe
 
 
 

slow NFS with Linux server

Post by Werner Kliewe » Wed, 21 Apr 1999 04:00:00


David,


> These options are set at the client side on a per mount basis. Set
> options with the mount command switch -o vers=nfs2,proto=tcp
> By default nfs uses udp.

Thanks for the pointer. I missed those options when looking at the man
page yesterday, but they DO exist in 4.2.1, so I will try them out. My
real concern is to be able to back up my laptop that runs linux to a
proper tape drive, but we also use nfs across production
AIX,Linux,HP/UX. If this makes a difference in performance it will be a
great help.

Werner Kliewer
Manitoba Public Insurance

 
 
 

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
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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
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nameserver.  I don't have a local name server setup.  

I have tried modifying some of the parameters below during the
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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,
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performance.

I did notice when I set the network up before the install that pinging
from
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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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