Rsync via network to slow server

Question

I am transporting lots of data with rsync from a Linux client to a NAS, both machines are connected via fast (100 Mbit) Ethernet. The NAS is a Linux-based "slow-CPU" D-Link DNS-323 with telnet and rsync support added. rsync is running as daemon on this box. I would like to speed up the transfer, if possible

The performance bottleneck is the NAS CPU, it is constantly 0% idle. ifstat reports an eth0 throughput of about 7 Mbyte/sec on the client, so the link is not yet saturated, I understand the NAS can handle up to 12 Mbyte/sec on fast ethernet.

I run rsync, both on client and NAS, with defaults, not explicitly enabling or disabling compression or encryption. I do not tunnel via ssh.

This is the rsyncd.conf on the NAS:

port = 873
use chroot = yes
pid file = /ffp/var/run/rsyncd.pid
[backup]
path = /mnt/HD_a2/backup
comment = Backup
read only = no

The daemon is started with

--daemon --config=/ffp/etc/rsyncd.conf 

command line arguments.

The client command line is plain

rsync -r -v <dir> rsync://<nas-ip>:873/backup 

Is there a way to reduce load on the NAS so that ultimately the network becomes the bottleneck?

Answer 1

For what you are doing with the DNS-323 (rsync over TCP), you are pretty much getting the expected throughput - which is actually put at nearer 5.5MB/Sec according to this page. I get similar speeds as you with rsync and my DNS-323.