[Samba] Maximum samba file transfer speed on gigabit...

Adam Nielsen adam.nielsen at uq.edu.au
Mon Jun 5 23:49:38 GMT 2006

> a single one of these SAS drives is supposed to sustain 90+ MB/s, and
> I have four of them raided together.

You should be able to do a crude test by creating a large file ("dd
if=/dev/random of=test.dat bs=1048576 count=100" will create a 100MB
test file) and then timing how long it takes to read the file back
("time dd if=test.dat of=/dev/null")  That'll tell you if your hard
drives are configured properly and reading at full speed.  Use a larger
file for a more accurate test.

> The NICs are testing out at nearly 1Gb/s.  Is there REALLY that much
> overhead for Samba?

I wouldn't think there'd be a huge overhead, but in my own experience
it's certainly noticeable (as compared to say FTP.)  Don't forget that
if the PC on the other end isn't capable of receiving the data at full
speed, then it doesn't matter how fast the server is.

You can test this by sharing the test file you created above, making it
suitably large to give you time to properly test, and then copy it onto
one of the other PCs via Samba.  This should theoretically max out the
network connection, but if your other PC sits at close to 100% CPU
usage, then the bottleneck is out there, not on the server.  If you map
a network drive and do it from a command prompt, you should be able to
do something like "copy test.dat nul" which under DOS at least would
read in the file but not write it to disk (note only one L in 'nul')


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