How to speed up rsync?

Question

I'm running rsync to sync a directory onto my external USB HDD. It's about 150 gigs of data. 50000+ files I would guess.

It's running it's first sync at the moment, but its copying files at a rate of only 1-5 MB/s. That seems incredibly slow for a USB 2.0 enclosure. There are no other transfers happening on the drive either.

Here are the options I used:

rsync -avz --progress /mysourcefolder /mytargetfolder

I'm running Ubuntu Server 9.10.

Answer 1

For the first sync just use

cp -a  /mysourcefolder /mytargetfolder

rsync only adds overhead when the destination is empty.

also.. the -z option is probably killing your performance, you shouldn't be using it if you are not transfering data over a slow link.

Answer 2

If you're using rsync with a fast network or disk to disk in the same machine,

not using compression -z

and using --inplace

speeds it up to the performance of the harddrives or network

compression uses lots of CPU

not using inplace makes the harddrive thrash alot (it uses a temp file before creating the final)

compression & not using inplace is better for doing it over the internet (slow network)

also, you don't get wirespeed if ton & tons of small files, but it's still faster

Answer 3

You don't say what size distribution your files have. If there are many small files then this will reduce overall transfer rate by increasing head movement latency in both the source and destination drives as the tool opens new files and the OS keeps directory entries and other metadata (such as the filesystem's journal if you are using meta-data journaling like ext3/ext4 and NTFS do by default) up to date during the transfer. A file copy proces will only "get into its stride" for larger objects, when a simple bulk transfer is happening.