[Samba] Samba -> WinXP: slow transfers, partial solution

jancio_wodnik at wp.pl jancio_wodnik at wp.pl
Mon Apr 16 11:35:28 GMT 2007

I have slow transfer from my samba serwer, casue my HDD wasn't running 
in UDMA mode, only in PIO, beside this a installed CentOS 4 and all 2 
disks are running in UDMA mode and there isn't a issue with network 
speed between WINXP SP2 and samba serwer.

Maybe check yours HDD too ?



Charles Marcus pisze:

>> I'm running Samba 3.0.24 as PDC and file server on Gentoo Linux, 
>> AMD64, 2.6.19 kernel, 100MBit/s network, and experience quite slow 
>> file transfers from Samba to WinXP SP2 clients: the speed is varying, 
>> but is about 1-2Mb/s at best.
> I'm assuming for the rest of this that you mean MB/sec not Mb/sec when 
> referencing transfer speeds...
>>  b) Transfering to/from Samba server from Gentoo Linux on the same PC 
>> where WinXP is installed (so, completely the same hardware and 
>> connection) is also at normal speed.
> So, you are running something in a VM?
>>  c) Transferring to/from WinXP to the server where Samba is installed 
>> using any other protocol (such as HTTPS or SCP) is also at normal speed.
> Define 'normal'...
>> 2) CPU is at almost idle level both at client and server, so it's not 
>> the issue.
>> 3) If there is any other network activity, transfer speed is 
>> increased up to normal level: f.e. doing two simulteneous transfers 
>> from Samba server to WinXP client gives 5Mb/s at each transfer, as 
>> expected.
> Again, define 'normal'?
> 100Mb network connections should give @ 12MB/sec transfer speeds, no? 
> So 5MB/sec speeds are certainly not 'normal'.
>> 4) Running tcpdump on server while the transfer is performed improves 
>> transfer speed in about 1.5 - 3 times, but still not to the normal 
>> speed.
> TCP dumps are fine, but you neglected to provide the most important 
> thing for initial troubleshooting assistance: where is your config?
>> 5) Playing with "socket options" does not give any results.
> Modern linux kernels (2.6+) do *not* need to have these values tuned, 
> so it is recommended to not set them *at* *all*. Just delete these 
> entries.
>> Specifically, using advices from the article 
>> http://www.dd.iij4u.or.jp/~okuyamak/Documents/tuning.english.html 
>> about SO_SNDBUF does not improve situation (but read below).
> Well, since this article is dated from 2000, I don't think I'd trust 
> it much.
>> 6) tcpdump + tcptrace show that there are a lot of retransmissions, 
>> see dumps below.
>> 7) I've tested several WinXP clients with different hardware, all 
>> with the same results.
> What about the NIC on the Samba server? If all clients are affected 
> the same, then that is the NIC you should focus on (if it is indeed a 
> hardware issue).
>> 8) Samba logs looks normal to me, nothing special.
>> Points (3) and (5), and also the article about SO_SNDBUF tuning gave 
>> me an idea that there might be smth wrong with ACKs sent from WinXP.
> I think you need to go back to square one, and start over, but with up 
> to date references - like the excellent 'Samba-3 By Example' and/or 
> 'The Official Samba-3 HOWTO and Reference Guide'.
>> It seems that I'm not the only one who have similar problems: see 
>> BUGs 2117 and 3706 in Bugzilla, and discussion at Gentoo mailing 
>> list: http://forums.gentoo.org/viewtopic-p-2820556.html
> This too is an old(er) thread - and it specifically mentions switching 
> from smbfs to cifs as the best solution...

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