I'm using Samba on Debian 8.4 (Jessie) to share files with a small number of Windows & Mac users (~20 total, ~5 at a time at most) and I'm seeing abysmal performance on read and write: tested by copying large file to and from the share, average < 500 KB/s.

I tested the disk by running dd if=/dev/zero of=/srv/temp.tmp ... and dd if=/srv/temp.tmp of=/dev/null ... and the disk can get to 70~80 MB/s so that's probably not the bottleneck.

I tested network by running iperf and even on the edge of the wifi I can get 4~5MB/s, in door it's ~10MB/s so I don't think it's network related either.

An interesting observation is that during my test (copying large file to/from the share) while running iostat -d -p md0 1 shows that the disk is not active all the time, but rather only read/write 1 sec for every ~10 sec inactive. This is not the case during the test with dd.

All the tests were performed when I was the only active user to rule out possible interferences. This is a fresh install of Debian with some other stuff (apache server, php, etc) and a default config of samba. The share config is as follow

  path = /srv
  force group = data
  read only = No
  create mask = 0660
  force create mode = 0660
  directory mask = 02770
  force directory mode = 02770
  • Are you sure your network is in MB/s and not Mb/s ? (Megabits, ie 8 times less information than a MegaByte [Byte=8bits]) , as 10Mbits/sec would yield what speed you are witnessing (the rest being taken up by other paquets). And then check samba.org/samba/docs/man/Samba-HOWTO-Collection/speed.html for a bunch of things to look for (read size, etc) – Olivier Dulac May 30 '16 at 13:56
  • Pretty sure it's megabyte, not megabit. iperf result is in megabit which I had divided by 8 before posting that to keep all the numbers consistent. – Binh Tran May 30 '16 at 14:35

To tune performance of Samba, the howto has a section about speed/performance tuning:


You can probably enhance your results by tuning : the read size, and the socket options, in particular, are worth tweaking.

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