Table of Contents
Fileserver
Testing
Network
A good way to test your network connection is with netcat and pv. Both are packaged by all major Linux distos.
On one machine run “nc -ulp 5000 > /dev/null”. This sets up a UDP listener on port 5000 and directs anything that is sent to it to /dev/null. Use UDP for this to avoid the overhead of TCP.
On the other machine, run “pv < /dev/zero | nc -u listenerhost 5000”, where “listenerhost” is the hostname or IP address of the listening machine. That will fire an unending stream of zero-filled packets across the network to the listener, and pv will print out an ongoing report on the speed at which the zeros are flowing.
Let it run for a while and watch the performance. If the numbers you're getting aren't over 100 MB/s – and they often won't be, on a typical Gig-E network – then don't worry about disk performance until you get that issue fixed. The theoretical limit on a Gig-E network is around 119 MBps.
Do the same thing without the “-u” options to test TCP performance. It'll be lower, but should still be knocking on 100 MBps. To get it closer to the UDP performance, you may want to look into turning on jumbo frames.
pv is also highly useful for testing disk performance, if you're building your own NAS (highly recommmended – a Linux box with 3-4 10K RPM SATA drives configured as software RAID0 array will generally kick the ass of anything other than very high end stuff. It's nearly always better than hardware RAID0, too).
NAS DIY
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