Rsync
Quick Usage Guide
Copying Files via SSH
To copy files from /export/backup to a remote location (on server 'backup'):
$ rsync -avz /export/backup/ -e ssh backup:/export/backup/
## Or with a non-standard SSH port
$ rsync -avz /export/backup/ -e "ssh -p 2222" backup:/export/backup/
With sudo on remote server
If you need to elevate your privileges with sudo when copying files on the remote system, specify an rsync path using sudo:
## With sudo on the remote host
$ rsync -avz --rsync-path="sudo rsync" -e "ssh -p 2222" user@remote:/path ./path
You also need to add rsync in the /etc/sudoers file:
username ALL=NOPASSWD:/usr/bin/rsync
Copying files with Progress Information
$ rsync -avh --progress /src/ /dst/
Limiting Bandwidth
The transfer rate can be limited with the --bwlimit=kbps option. Bytes per second is the default if no unit is given.
## Limit transfer speed to 1MB/s
$ rsync --bwlimit=1024 /source/ /destination/
$ rsync --bwlimit=1m /source/ /destination/
Parallel Copy
You may wish to run multiple rsync in parallel to speed up data transfers.
## Transfers /source/directory tot /destination/directory with 5 parallel jobs
$ ls -1 /source/directory/ \
| xargs -I {} -P 5 -n 1 rsync -avh --progress /source/directory/{}/ /destination/directory/{}/
Excluding a Directory
If your source has snapshot directories (such as .snapshots) which aren't hidden by your filesystem by default, you can exclude it from being copied by using the --exclude directory option. Eg:
$ rsync --exclude .snapshots -avh --progress /source/ /destination/
Copying Directories
Because I've been bitten by this issue way too many times in the past couple of days, to avoid copying a directory into another directory, always have a trailing slash from the source.
In more depth, suppose I have a src directory and I want its contents to be replicated in dst.
## This copies 'src' into 'dst/src'
$ rsync -avh src dst
## This too copies 'src' into 'dst/src'
$ rsync -avh src dst/
## Works as expected. Contents in src is now in dst
$ rsync -avh src/ dst
## Works as expected as well
$ rsync -avh src/ dst/