[Samba] slow streaming but fast copy
Tom Van den Eynde
I have some very strange problems with samba on my shiny new server.
The first problem was that file transfers were very slow (copying a
file of 700Mb took 50 minutes over 100Mbit network). I checked other
protcols (ftp/http/scp) on the server and they were able to use the
100Mbit link for full. After a lot of debugging, I found that the
problem was related to oplocks. When disabling oplocks, the same file
was copied in just under 2 minutes.
However a second problem occured. Although copying files of the samba
file share works perfectly, playing mp3 files of the share does not.
When I open up any mp3 player and want to play a file, it stutters and
it is impossible to listen to. With Winamp, I mangaged to get some
quality by setting the buffer to 100Mb but I don't want to do this at
every pc and in every mp3 client.
I tried different settings (tcp_nodelay, SNDBUF, SRVBUF, TCP_TOS) but
no effect there.
I also ran a tcpdump when copying a file (good) and when streaming a
file (bad) but there are no noticable differences there.
On the samba server, there is also a VMware server running so I tried
setting up a Win VM in there (on the same physical server) and when I
stream files from the Windows VM, I have no problems whatsoever
This leads me to believe that there is a problem with either samba or
the linux kernel.
The server specs are the following:
Hardware: Core 2 Duo 6600, 2 GB DDR RAM, 500 GB SATA, Asus Mobo with
Realtek 10/100/1000 NIC
OS: Debian Stable 3.1, Linux Version 2.6.19.1 SMP
SAMBA: 3.0.23d (from apt repository at samba.org)
Sanitized smb.conf:
[global]
panic action = /usr/share/samba/panic-action %d
workgroup = TESTGROUP
netbios name = server
server string = VDE Server
hosts allow = 1.2.3.4
printcap name = cups
load printers = yes
printing = cups
log file = /var/log/samba/log.%m
max log size = 500
log level = 1
security = user
encrypt passwords = true
passdb backend = tdbsam
smb passwd file = /etc/samba/smbpasswd
unix password sync = Yes
passwd program = /usr/bin/passwd %u
passwd chat = *New*UNIX*password* %n\n *ReType*new*UNIX*password*
%n\n *passwd:*all*authentication*tokens*updated*successfully*
socket options = TCP_NODELAY
oplocks = no
level2 oplocks = no
interfaces = 1.2.3.4/24
local master = yes
os level = 65
domain master = yes
preferred master = yes
time server = yes
domain logons = no
wins support = yes
dns proxy = yes
preserve case = yes
short preserve case = yes
case sensitive = no
[mp3]
path = /home/mp3
comment= MP3 disk
public = yes
guest ok = yes
writable = yes
printable = no
force user = nobody
force group = nogroup
Does anyone has a clue what might be wrong?
Oh yeah, the same smb.conf worked perfectly on the old server (with
oplocks enabled that is)
Many thanks,
Kind regards,
Tom
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Tom Van den Eynde
I wanted to update you on progress made.
I downgraded my samba package from the latest samba.org debian stable
package to the stock debian package which came with the latest sarge (samba
3.0.14a-Debian).
I re-enabled oplocks for my configuration.
After this I noticed the following:
- Playing MP3's from the network share(s) improved but is not yet optimal
- Playing Video's from the network share(s) still is an issue
- copying a large file (700 MB ISO) from the share(s) sometimes takes a long
time:
- It only takes a long time if an oplock EXCLUSIVE+BATCH is granted
- when the oplock breaks (and returns to Level II or none), copying
goes lightning fast!
- I have increased the debugging level but don't see any differences in
logging between a correct (fast) copy a slow copy
Could this have something to do with my CPU/kernel configuration (see
original below)?
Or maybe someone knows extra debugging, steps, I might take to tackle this
issue?
I am getting desperate in this matter ;-)
Kind regards,
Tom
Jason Haar
> - I have increased the debugging level but don't see any differences in
> logging between a correct (fast) copy a slow copy
>
>
performance. We were seeing only 50Mbs on Samba servers (with 100M
cards) and couldn't figure out what was wrong. Then we noticed "log
level = 9" ;-) Turning that off kicked performance up to 80Mbs - which
is equivalent to our Win2K3 servers.
--
Cheers
Jason Haar
Information Security Manager, Trimble Navigation Ltd.
Phone: +64 3 9635 377 Fax: +64 3 9635 417
PGP Fingerprint: 7A2E 0407 C9A6 CAF6 2B9F 8422 C063 5EBB FE1D 66D1
Tom Van den Eynde
As mentioned in the original mail, I also did tests with the latest binary packages from samba.org but theses gave me even worse performance.
Debug Level logging is turned off. I only enabled it during some tests (and then only one client was connect to a Core 2 Duo machine so the machine was not really loaded :) )
Tom