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how to spec a server that will accept NFS connections...

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Rahul...
Posted: Wed Sep 02, 2009 11:40 am
Guest
I have a master server that much accept NFS mounts from ~300 other
machines. Each of the slave machines has a 2-gigabit bonded port.

In anticipation of the high network loads on the master-node would it be
worthwhile to get it set up with a 10gigabit eth card? Anything else that
could be done? How about on the switch? Can I get a switch with one or a
few high speed ports so that the master node plugs into a high speed pipe?

The server is going to be a Intel Nehalem E5520 with about 16 GB RAM. Sound
reasonable? Or should I be ramping up RAM etc?

Finally, I heard rumors that NFS is pretty passe especially for large
installations. Any good alternatives?

--
Rahul
 
The Natural Philosopher...
Posted: Thu Sep 03, 2009 4:31 am
Guest
Rahul wrote:
Quote:
I have a master server that much accept NFS mounts from ~300 other
machines. Each of the slave machines has a 2-gigabit bonded port.


NFS over UDP or TCP?

Quote:
In anticipation of the high network loads on the master-node would it be
worthwhile to get it set up with a 10gigabit eth card? Anything else that
could be done? How about on the switch? Can I get a switch with one or a
few high speed ports so that the master node plugs into a high speed pipe?

The server is going to be a Intel Nehalem E5520 with about 16 GB RAM. Sound
reasonable? Or should I be ramping up RAM etc?

Finally, I heard rumors that NFS is pretty passe especially for large
installations. Any good alternatives?
 
Chris Cox...
Posted: Thu Sep 03, 2009 12:23 pm
Guest
On Wed, 2009-09-02 at 21:40 +0000, Rahul wrote:
Quote:
I have a master server that much accept NFS mounts from ~300 other
machines. Each of the slave machines has a 2-gigabit bonded port.


Quote:
In anticipation of the high network loads on the master-node would it be
worthwhile to get it set up with a 10gigabit eth card? Anything else that
could be done? How about on the switch? Can I get a switch with one or a
few high speed ports so that the master node plugs into a high speed pipe?

10gE is not well understood by most. But even so, you will in theory
get better performance regardless of expertise with 10gE.

If you have any really old NFS clients out there, don't do this. UDP
requests will lead to bad things happening. This is a known issue.
Most anything in the past 10 years or so is not a problem.

Quote:

The server is going to be a Intel Nehalem E5520 with about 16 GB RAM. Sound
reasonable? Or should I be ramping up RAM etc?

That's ok. Reasonable (on the extreme side). I use a LOT less and
serve up well over 100 clients without issue.. just 1Gbit network. They
usually get 30+MB/sec or so.... so, not terribly shabby. Single client
benchmark (last one I did before going live on the 1Gbit network) showed
92MB/sec on seq. read and 60MB/sec on seq. write (random io was good in
the 40-50MB/sec range)... which might not be picture perfect, but good
enough (same network as normal traffic, no jumbo frames). We don't have
any bonded clients... pure 1Gbit non aggregated.

We lost a drive on an old HPUX box, replacing the HVD drive would cost
about $800 for just 9.1G, so we NAS'd the area instead. Now, that box
is just 100mbit and we're getting better performance off the NAS than
what we did with the actual drive!!

Our servers right now have dual 5130's and 8G. We were running dual
P4-ish Xeons. a E5520 is a LOT faster than a 5130, even a pair of them.
The need for 16G depends on the number of nfsd's you're going to run and
the amount of load. Not sure if you'll be able to fully utilize the
space and get any real benefit.

Our NAS is split into two servers each serving up about 2TB max. Each
is a DL380G5 2x5130 with 8G ram with 8 nfsd's each. Backend storage
comes off a SAN. Both are running SLES10SP1 currently. Just checked,
one is serving to about 150 client hosts and the other about 110. TONS
of free memory. No evidence of them EVER swapping. So I still think
16G is overkill.

In case it matters, our SLES based NAS serves to just about every
*ix vendor/version imagineable. We have clients using NFS v2 and v3.

There were too many issues with NFSv4 for us to move forward with that
when the NAS was last updated (SLES10SP1 should give a hint with regards
to age). Not sure I trust NFSv4 even today.

Quote:

Finally, I heard rumors that NFS is pretty passe especially for large
installations. Any good alternatives?

yes and no. There are alternatives out there, but nothing that works
everywhere. So if you have a mixture of clients, NFS is still very
useful.

AFS (e.g. OpenAFS) is often cited as a better NFS. Using an sshfs mount
works for many as a higher speed simulated NAS. Really depends on what
exactly you need.

You can look into pNFS as well.

And there's always CIFS... :-)

And the usual fair of high end standalone products from NetApp, EMC,
etc.
 
Rahul...
Posted: Wed Sep 09, 2009 7:46 am
Guest
The Natural Philosopher <tnp at (no spam) invalid.invalid> wrote in news:h7o5tj$fro$2
at (no spam) news.albasani.net:

Quote:
NFS over UDP or TCP?


Either way is OK to me. I am not really sure what I am used to using. This
is a closed environment with its own switches, address space and LAN. So I
guess whichever option gives the better performance TCP or UDP.


--
Rahul
 
The Natural Philosopher...
Posted: Wed Sep 09, 2009 2:32 pm
Guest
Rahul wrote:
Quote:
The Natural Philosopher <tnp at (no spam) invalid.invalid> wrote in news:h7o5tj$fro$2
at (no spam) news.albasani.net:

NFS over UDP or TCP?


Either way is OK to me. I am not really sure what I am used to using. This
is a closed environment with its own switches, address space and LAN. So I
guess whichever option gives the better performance TCP or UDP.


Its along time..since SUNOS4 servers, but ISTR RAM wasn't a problem, and

neither really was CPU..the actual interfaces need to be good..dual
ethernet as fast as you can, or maybe optical..depending on what the
users are doing, they EXPECT high burst speed, but the actual total
throughput may not be a lot.

You can solve the disk speed stiff with RAM caching (default begaviour)
and maybe RAID. apart from that, quality Ethernet or optical cards is
all you need.

IIRC TCP menas a process per connection, so 300 processes times how many
mounts you have per user...they aren't huge tho, UDP means you set up a
lot less processes, but there may be a bit of a lag..its been a long
time now. dont take this as gospel. I do seem to remember getting less
performance off NFS than SAMBA at one time.
 
Rahul...
Posted: Thu Sep 24, 2009 3:51 pm
Guest
Chris Cox <chrisncoxn at (no spam) endlessnow.com> wrote in
news:1252002208.6805.128.camel at (no spam) geeko:

Thanks Chris! Sorry, I never noticed your very useful reply.

Quote:
If you have any really old NFS clients out there, don't do this.

None. All new machine. So then I ought to do NFS over UDP? Where exactly
is this specified. UDP versus TCP.

Quote:
That's ok. Reasonable (on the extreme side). I use a LOT less and
serve up well over 100 clients without issue.. just 1Gbit network.

These are HPC nodes though. Notorious for doing lot of I/O and do it
24/7.


Quote:
They usually get 30+MB/sec or so.... so, not terribly shabby. Single
client benchmark (last one I did before going live on the 1Gbit
network) showed 92MB/sec on seq. read and 60MB/sec on seq. write
(random io was good in the 40-50MB/sec range)...

I just posted bonnie++ output from my similar (but much smaller) NFS
setup.

http://dl.getdropbox.com/u/118481/io_benchmarks/bonnie_op_node25.html

I'm still trying to figure out which ones of your numbers to compare with
which of mine corresponding numbers! :)

which might not be
Quote:
picture perfect, but good enough (same network as normal traffic, no
jumbo frames).

Should I use jumbo frames? I mean no compatibility issues for me. All
this is my private network end-to-end.


Quote:
Our NAS is split into two servers each serving up about 2TB max. Each
is a DL380G5 2x5130 with 8G ram with 8 nfsd's each. Backend storage
comes off a SAN. Both are running SLES10SP1 currently. Just checked,
one is serving to about 150 client hosts and the other about 110.
TONS of free memory. No evidence of them EVER swapping. So I still
think 16G is overkill.


Any way to check what;s the RAM utilization of my current NFS server
setup? I tried nfsstat but it won't show me anything useful.



--
Rahul
 
Jerry McBride...
Posted: Tue Sep 29, 2009 8:04 am
Guest
Chris Cox wrote:

Quote:


On Fri, 2009-09-25 at 01:51 +0000, Rahul wrote:
Chris Cox <chrisncoxn at (no spam) endlessnow.com> wrote in
news:1252002208.6805.128.camel at (no spam) geeko:

Thanks Chris! Sorry, I never noticed your very useful reply.

If you have any really old NFS clients out there, don't do this.

None. All new machine. So then I ought to do NFS over UDP? Where exactly
is this specified. UDP versus TCP.

NO. No you do NOT want to use UDP. It's just really old systems that
had this restriction.

NFS UDP over "high speed" networks (gigabit) will result in corruption.


That's ok. Reasonable (on the extreme side). I use a LOT less and
serve up well over 100 clients without issue.. just 1Gbit network.

These are HPC nodes though. Notorious for doing lot of I/O and do it
24/7.


They usually get 30+MB/sec or so.... so, not terribly shabby. Single
client benchmark (last one I did before going live on the 1Gbit
network) showed 92MB/sec on seq. read and 60MB/sec on seq. write
(random io was good in the 40-50MB/sec range)...

I just posted bonnie++ output from my similar (but much smaller) NFS
setup.

http://dl.getdropbox.com/u/118481/io_benchmarks/bonnie_op_node25.html

Not great. This was an NFS test across gigabit?? Reads look bad.

With that said, there are good versions of bonnie++ and bad versions.
What version did you use?

But still, I'm not aware of a version of bonnie++ that had a problem
with block reads.


I'm still trying to figure out which ones of your numbers to compare with
which of mine corresponding numbers! :)

which might not be
picture perfect, but good enough (same network as normal traffic, no
jumbo frames).

Should I use jumbo frames? I mean no compatibility issues for me. All
this is my private network end-to-end.

Probably NOT. You can convert to jumbo frames IF ALL NICS are running
Jumbo frames (whole network NO EXCEPTIONS). If you don't, you'll get
frame errors all over the place.


Don't forget... along with jumbo frame compatible mic's, you'll need the same
compatibility in your switch boxes...


Quote:


Our NAS is split into two servers each serving up about 2TB max. Each
is a DL380G5 2x5130 with 8G ram with 8 nfsd's each. Backend storage
comes off a SAN. Both are running SLES10SP1 currently. Just checked,
one is serving to about 150 client hosts and the other about 110.
TONS of free memory. No evidence of them EVER swapping. So I still
think 16G is overkill.


Any way to check what;s the RAM utilization of my current NFS server
setup? I tried nfsstat but it won't show me anything useful.

free?

I've got a pretty heavily hit setup... we just have 8G of ram... and I
doubt we ever use it all.

--

*****************************************************************************

From the desk of:
Jerome D. McBride

10:03:35 up 1 day, 15:43, 4 users, load average: 0.10, 0.13, 0.15

*****************************************************************************
 
 
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