The Samba-Bugzilla – Bug 10856
Samba upload speed over WiFi drops after some seconds
Last modified: 2014-11-23 01:40:21 UTC
I'm using Samba to up- and download files on/from my NAS.
Uploading files on my NAS using SMB is quite depressing. The upload speed begins at around 4.5 MB/s (like on Windows 7 all the time) and then collapses to around 0.6 MB/s after some seconds (10 – 20 secs). The iwlwifi driver "works perfectly" (see URL), but I don't find any Samba error message in the syslog, but something is definitely wrong.
Try doing an ftp transfer without Samba being involved over the same wifi connection. That will give you more data on how much SMB is affecting the problem.
FTP works without any problems as good as SMB on Windows.
So SMB is very sensitive to packet loss, with the default algorithms on a Linux server. What is your NAS make of ?
My NAS is a QNAP TS-110 with latest firmware version 4.1.1 running Samba version 3.6.23.
OK, this almost certainly isn't a Samba problem, but a Linux TCP issue dealing with a lossy network.
Check this out:
and I'd try:
echo "westwood" > /proc/sys/net/ipv4/tcp_congestion_control
Thanks for the link.
The "cubic" algorithm is selected currently.
The upload speed is going up and down continuously (from 100 kB/s – 3000 kB/s) with the "westwood" algorithm. Not really an improvement to the 600 kB/s before.
No idea what's going wrong?
Is it a TCP bug?