Samba and Gigabit Ethernet

I have XP on a 2.4 P4 talking to Fedora Core 3 on a 2.0 Celeron
connected by 100 MHz Ethernet. XP accesses Samba shares on
Linux.

How much faster would Gigabit Ethernet?

Does Linux support the cheap gigabit ethernet boards?
--
Chuck Forsberg caf@omen.com www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

Chuck Forsberg wrote:
> I have XP on a 2.4 P4 talking to Fedora Core 3 on a 2.0 Celeron
> connected by 100 MHz Ethernet. XP accesses Samba shares on
> Linux.

Do you know your current throughput with 100Mbps? How close does it
crowd your hard disk throughput? At clients? At server? Where's the
bottleneck?

> How much faster would Gigabit Ethernet?

See above and realize that _many_ people are "satisfied" with only
300-400Mbps on the wire. Will that exceed your disk throughput? Solve
your problems?

> Does Linux support the cheap gigabit ethernet boards?

Depends on the chipset(s) used on the nic(s). Can also depend on any
switches/routers along the pathway. Cheaper cards stress the OS/cpu
more than "server" grade cards which offer more on card
processing/memory.

GigE generates _lots_ of hardware interrupts and can really stress a
machine if not properly set up. "Tweaking" the setup so it _is_ proper
is more work than many people are willing to persue. Don't expect
miracles or a painless upgrade path. This is why so many folks settle
for ~350Mbps.

What hardware do you currently have on hand? Willing to replace any of
it? Use Goolge to see how Linux supports your current hardware in a
GigE network. What do you expect GigE to provide that your current
setup does not? More speed? Greater reliability? Easier setup?
Easier troubleshooting?

If you already have all the pieces, just try it out and see what you
get.

If you are thinking of buying new toys, I usually tell people not to
bother unless they have a bandwidth problem that they think GigE will
solve/lessen.

If you're willing to experiment and want to learn, go ahead ;)

good luck,
prg

"Chuck Forsberg" <caf@omen.com> wrote in message
news:mqmdnQU5hNVd2PjfRVn-rQ@giganews.com...

>I have XP on a 2.4 P4 talking to Fedora Core 3 on a 2.0 Celeron
> connected by 100 MHz Ethernet. XP accesses Samba shares on
> Linux.
>
> How much faster would Gigabit Ethernet?

Probably not much. You would probably due better to tune Samba.

> Does Linux support the cheap gigabit ethernet boards?

Yes.

DS

Chuck Forsberg <caf@omen.com> wrote:
> I have XP on a 2.4 P4 talking to Fedora Core 3 on a 2.0 Celeron
> connected by 100 MHz Ethernet. XP accesses Samba shares on Linux.

> How much faster would Gigabit Ethernet?

Samba is a request/response sort of thing right? That being the case,
the gains may not be "huge." The smaller the requests and responses,
the less then gain.

In and of itself gigabit ethernet (the IEEE spec) does _nothing_ to
make sending/recieving data any easier on the host. In broad
handwaving terms, it will take just as many CPU cycles to transfer a
KB of data over Gigabit Ethernet as it did over 100Base-T as it did
over Classic Ethernet, as it will over 10 Gigabit Ethernet. The
official MTU sizes are all the same, slapping an Ethernet header is
about the same on all of them etc etc...

Now, as the technologies have evolved, the _implementations_ of those
things have gotten better. Programming models for GbE NICs _tend_ to
be better than the 100BT NICs before them and so on. Also, "off-spec"
things have been added such as support for CKO - ChecKsum Offload,
Jumbo Frames and/or "large send/TSO - Transport Segmentation Offload."
Those can offload some overhead from the host.

rick jones
--
firebug n, the idiot who tosses a lit cigarette out his car window
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to raj in cup.hp.com but NOT BOTH...

prg wrote:
> Chuck Forsberg wrote:
>
>>I have XP on a 2.4 P4 talking to Fedora Core 3 on a 2.0 Celeron
>>connected by 100 MHz Ethernet. XP accesses Samba shares on
>>Linux.
>
>
> Do you know your current throughput with 100Mbps? How close does it
> crowd your hard disk throughput? At clients? At server? Where's the
> bottleneck?
>
Well, lets see. IDE throughput is effectively 20MiB-60MiB/s. Thats
~160mbits to 480mbits. So I suppose that means that you can boot a PC
over the lan just as fast as from a fixed disc?

Hmm, so what about a pc with 2-3-4GB of ram, a ramdisk, with the lan
bootable OS, such as XP or Linux.

The bottleneck for booting up a PC is the disk speed. Mostly.
So you should be able to boot XP, I would guess, half the time, if you
boot from a ramdisk over gigabit ethernet!

Well--- that is if the speed is closer to 800mbits!

Anyone got any actual throughput measurements?

Google:
Two way to increase performance

Increase the minimum packet length

Decrease the distance span

Multiple transmissions arriving simultaneously results in all packets
being lost for a typical hub

Ouch, this particular test peaked 160Mbits.

Ooh, another test - FreeBSD makes linux look like windows when it comes
to lan performance and throughput at gigabit levels! Wow!

Shit people, I cant find any gigabit bandwidth measurements exceeding
160Mbps! Do I have to test EVERYTHING myself? Will do a measurement and
post it here..


Well Well. http://sd.wareonearth.com/~phil/jumbo.html says you should
use "Jumbo frames" (9000 bytes instead of 1500!) This halves your cpu
usage and adds 30% to your thoughput. Dont think its compatible with
slower networks though, but its not a bad trade! You cant go bigger than
12000 bytes packets because of the CRC field. (Haha, IPv6 has got a 4GB
packet size limit! Geeez!)


>
>>How much faster would Gigabit Ethernet?
>
>
> See above and realize that _many_ people are "satisfied" with only
> 300-400Mbps on the wire. Will that exceed your disk throughput? Solve
> your problems?
>
>
>>Does Linux support the cheap gigabit ethernet boards?
>
>
> Depends on the chipset(s) used on the nic(s). Can also depend on any
> switches/routers along the pathway. Cheaper cards stress the OS/cpu
> more than "server" grade cards which offer more on card
> processing/memory.
>
> GigE generates _lots_ of hardware interrupts and can really stress a
> machine if not properly set up. "Tweaking" the setup so it _is_ proper
> is more work than many people are willing to persue. Don't expect
> miracles or a painless upgrade path. This is why so many folks settle
> for ~350Mbps.
GigE being Gigabit Ethernet obviously!
>
> What hardware do you currently have on hand? Willing to replace any of
> it? Use Goolge to see how Linux supports your current hardware in a
> GigE network. What do you expect GigE to provide that your current
> setup does not? More speed? Greater reliability? Easier setup?
> Easier troubleshooting?
>
> If you already have all the pieces, just try it out and see what you
> get.
>
> If you are thinking of buying new toys, I usually tell people not to
> bother unless they have a bandwidth problem that they think GigE will
> solve/lessen.
>
> If you're willing to experiment and want to learn, go ahead ;)
>
> good luck,
> prg
>

David Schwartz wrote:
> "Chuck Forsberg" <caf@omen.com> wrote in message
> news:mqmdnQU5hNVd2PjfRVn-rQ@giganews.com...
>
>
>>I have XP on a 2.4 P4 talking to Fedora Core 3 on a 2.0 Celeron
>>connected by 100 MHz Ethernet. XP accesses Samba shares on
>>Linux.
>>
>>How much faster would Gigabit Ethernet?
>
>
> Probably not much. You would probably due better to tune Samba.
No no no no no!
It will be at least 3-5 times faster! Which is a lot. A copy that used
to take 5 minutes will easily take only a few seconds!

>
>
>>Does Linux support the cheap gigabit ethernet boards?
>
>
> Yes.
>
> DS
>
>

Rick Jones wrote:
> Chuck Forsberg <caf@omen.com> wrote:
>
>>I have XP on a 2.4 P4 talking to Fedora Core 3 on a 2.0 Celeron
>>connected by 100 MHz Ethernet. XP accesses Samba shares on Linux.
>
>
>>How much faster would Gigabit Ethernet?
>
>
> Samba is a request/response sort of thing right? That being the case,
> the gains may not be "huge." The smaller the requests and responses,
> the less then gain.
>
> In and of itself gigabit ethernet (the IEEE spec) does _nothing_ to
> make sending/recieving data any easier on the host. In broad
> handwaving terms, it will take just as many CPU cycles to transfer a
> KB of data over Gigabit Ethernet as it did over 100Base-T as it did
> over Classic Ethernet, as it will over 10 Gigabit Ethernet. The
> official MTU sizes are all the same, slapping an Ethernet header is
> about the same on all of them etc etc...
>
> Now, as the technologies have evolved, the _implementations_ of those
> things have gotten better. Programming models for GbE NICs _tend_ to
> be better than the 100BT NICs before them and so on. Also, "off-spec"
> things have been added such as support for CKO - ChecKsum Offload,
> Jumbo Frames and/or "large send/TSO - Transport Segmentation Offload."
> Those can offload some overhead from the host.
>
> rick jones
I hardly think modern CPU's are the bottlenecks for any type of linear
data processing!

Maybe on a PII or low-end PIII, yes! But gee, any post Ghz machine can
surely work magic... on a byte processing level!

"Coenraad Loubser" <c10u@ananzi.co.za> wrote in message
news:d43tbo$eri$2@ctb-nnrp2.saix.net...

> David Schwartz wrote:

>> Probably not much. You would probably due better to tune Samba.

> No no no no no!
> It will be at least 3-5 times faster! Which is a lot. A copy that used to
> take 5 minutes will easily take only a few seconds!

A copy is not a very realistic test. Try compiling over samba.

DS

To answer the questions that have been raised:
The applications where the speed would make a difference
are similar to copies - some unidirectional, some not.
One machine has a GbE on its motherboard, so I would need
cable, hub and a NIC for Linux. Time to start looking
for hardware.
--
Chuck Forsberg caf@omen.com www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

Chuck Forsberg <caf@omen.com> wrote:
> To answer the questions that have been raised: The applications
> where the speed would make a difference are similar to copies - some
> unidirectional, some not. One machine has a GbE on its motherboard,
> so I would need cable, hub and a NIC for Linux. Time to start
> looking for hardware.

Terminology nit - since "hub" implies "not switch" and implies
"half-duplex" finding a gigabit ethernet hub is going to be something
of a challenge. I used to claim there was no half-duplex GbE kit out
there, but IIRC someone corrected me on that a while back so I'll just
say that it is really rare :)

rick jones
--
a wide gulf separates "what if" from "if only"
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to raj in cup.hp.com but NOT BOTH...