poor Samba performance

BillyIdle · Posted: Wed Aug 16, 2006 10:30 pm Post subject: poor Samba performance

Hi there,

I have some serious samba performance issues and have no idea why.

My network is a gigabit network. It isn't the best hardware, so I don't expect any performance wonders here, but I think 2 MB/s is definitely too slow. I've tested other transfer methods, like ftp and scp and I always get more throughput. With FTP I have around 35-40 MB/s.

The samba-config is nothing special. I've post it at the bottom of this post.

The linux machine is an AMD Duron with 1.8 Ghz and 1,25 GB RAM. I've tried to transfer it with different client machines and with the linux tool "dbench" (set with 10 Clients).

Versions:
- net-fs/samba-3.0.22-r3 USE="automount readline syslog -acl -async -cups -doc -examples -kerberos -ldap -ldapsam -libclamav -mysql -oav -pam -postgres -python -quotas -swat -winbind -xml
- gentoo-sources-2.6.17-r4

I've tested it with two HDDs, one is an normal 20GB PATA HDD and one is an Samsung 250 GB SATA HDD. I've tested them with hdparm and bonnie++ and their values seems to be okay. There is no iptables or something like that which hangs between this traffic.

So, finally, my samba config (I have stripped down some comments):

palatin · Posted: Thu Aug 17, 2006 9:12 am Post subject:

For a start, you may want to look into changing the 'read size' option, as it may seem to harm performance when set too low.

I stumbled upon Samba tuning, which might help you further.
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Janne Pikkarainen · Posted: Thu Aug 17, 2006 9:38 am Post subject:

Try to make these bigger: SO_RCVBUF=2048 SO_SNDBUF=2048

Two kb buffer seems a bit small.
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BillyIdle · Posted: Thu Aug 17, 2006 1:28 pm Post subject:

Hi there,

thanks for the answers.

I've experimented a little bit with that what you said. With little sucess: I'm now at ~3 MB/s, which is better than before but not even as high as expected.

My "speed optimized settings" are now like this:

Janne Pikkarainen · Posted: Thu Aug 17, 2006 4:32 pm Post subject:

Ok. That kind of rapid speed stall is usually symptom of some kind of network problem. TCP/IP tends to drop speed if it encounters some errors or other problems during transmission.

What kind of transfer rates do you get with other protocols? You already mentioned "faster", but anywhere near 35-40 MB/s?
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BillyIdle · Posted: Thu Aug 17, 2006 9:52 pm Post subject:

Hi again,

thanks for your attention at all :-)

First of all, I have to correct an error: The real transferate is NOT 2 MB/s, it's even worse ... 0.17 MB/s it's the value. I was a little bit confused with smbtorture output (had 10 Clients as option).

I have tested two other protocols, one time FTP, one time SCP. They are both faster than smb. FTP comes to 35-40 MB/s as I mentioned before. The SCP transfer rate I don't remember exactly, it was something around 2 MB/s, which is very low as well.

What I've done now is the following two things:

- tried another distribution: result is the same like gentoo
- tried another NIC: result is also the same.

I have simply no other idea for now. Maybe I will test this whole thing on another machine tomorrow. I'm glad about every tip that I'm receiving, so thanks in advance and thanks for the already existing posts on this topic :-)

darkphader · Veteran Joined: 09 May 2002 Posts: 1225 Location: Motown

You might try a later release, there's an ebuild in the bug database for 3.0.23b (I created this edited ebuild and use it in production on 3 different servers).
Also I believe "syslog" is still experimental, plus you're not linking against cups (-cups in your use), yet you specify it in your smb.conf ( printcap name = cups, printing = cups). You may want to straighten that out and for a test try with -automount as well.

Also verify you have solid name resolution. Try populating your lmhosts files.

Chris
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Janne Pikkarainen · Posted: Fri Aug 18, 2006 8:53 am Post subject:

Have you tried to snoop with Ethereal... err.... Wireshark what happens during SMB transfers?
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BillyIdle · Posted: Fri Aug 18, 2006 8:54 am Post subject:

Hi darkphader,

unfortunately the gentoo bug database search is not working ... I've tried it several times, but I get no search result, it hangs by "Please stand by ..." since 30 minutes. Can you provide me another link to your ebuild so I can use it?

The cups thing is something I want to get rid of anyway, because I don't use any printers on this machine. I will change the use-flags for the two other things as well. Maybe that helps a little bit.

Is the name resolution in my case important? All tests were done with the exact IP adress, no hostnames or something like that. I will test it anyway. Thanks for all your advises.

BillyIdle · Posted: Fri Aug 18, 2006 8:54 am Post subject:

@Janne:

I will test that to, stands on my ToDo list :-)

BillyIdle · Posted: Fri Aug 18, 2006 2:00 pm Post subject:

So, news from the samba front

I've updated to samba version 3.0.23b with the ebuild that darkphader kindly provided. And I removed all the printing / cups things, I don't use it anyway. -automount and -syslog in the USE-Flags is also set.

What I have now is a speed between 0.25 MB/s and 0.40 MB/s according to smbtorture. The command I use is:

Janne Pikkarainen · Posted: Fri Aug 18, 2006 4:21 pm Post subject:

Now that I think of it... I haven't even used smbtorture before :lol:

Have you tried to transfer single big files with smbclient?
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Yes, I'm the man. Now it's your turn to decide if I meant "Yes, I'm the male." or "Yes, I am the Unix Manual Page.".

darkphader · Veteran Joined: 09 May 2002 Posts: 1225 Location: Motown

BillyIdle · Posted: Fri Aug 18, 2006 7:44 pm Post subject:

Hi there,

thanks for the replies :-)

darkphader: Do you mean the command for smbtorture? Or what? The command was/is: "smbtorture //192.168.12.254/netshare -U billy%test NBENCH" like posted before.

I've tried it with smbclient and get rates from 19 to 20 MB/s on an 100 MBit Card. Is smbtorture completely different in its benchmark ways, or what?

Even if 20 MB/s is way better than before, it's not what I'm expecting (because I get much higher rates with other protocols).

What I will do now, is to get an better GBit NIC, because my old one sucks as I found out and I'll check smbtorture with the new samba 4 suite.

So, from one point of view, it's now better, but 20 MB/s is even not that what I'm expecting ... is there more I can do about the samba perfomance?

tgh · Apprentice Joined: 05 Oct 2005 Posts: 222

While I suspect my experience with Samba won't help you... I run samba on a newer Asus A8V motherboard (I think Marvell 88E8001 gigabit NIC). Some Windows machines would seem to talk to the box at full speed or talk to other boxes at full speed (I tried various configurations). Connecting to the box directly with other TCP/IP tools showed good performance, just not for Samba.

I finally upgraded my kernel last week to the latest for gentoo-sources and I'm now seeing much higher data rates to/from the box for Samba. So I suspect that the Marvell driver got tuned up in the past 6 months and now works better.

(I generally hear good things about Intel NICs.)