Hi,

rsync is a powerful tool for syncing or backup folders. This post describes the parameters I usually use.

michael@debdev ~# rsync -a ~/MyStuff michael@devdeb2:/home/michael/MyStuff

 -a => means -rlptgoD

 -r, --recursive             recurse into directories
 -l, --links                 copy symlinks as symlinks
 -p, --perms                 preserve permissions
 -t, --times                 preserve modification times
 -g, --group                 preserve group
     --devices               preserve device files (super-user only)
     --specials              preserve special files
 -o, --owner                 preserve owner (super-user only)
 -D                          same as --devices --specials
  --devices                    preserve device files (super-user only)
  --specials                   preserve special files

other very usefull options:

-P                          same as --partial --progress
  --partial                 keep partially transferred files
  --progress                show progress during transfer

-u, --update                skip files that are newer on the receiver

-z, --compress              compress file data during the transfer

-v, --verbose               increase verbosity

--stats                 give some file-transfer stats
# Full sync delete files in destination which not exist in source
--delete                delete extraneous files from destination dirs
# On Fullsync just rename a file instead of delete them when it not exist in source
-b --suffix=.bak

--numeric-ids           don't map uid/gid values by user/group name of source and target. Just copy the numerical user/group ids

And as a full command line. This example uses ssh as transport protocol and requires that rsync is installed an both, the source and the target machine.

 
michael@debdev ~# rsync -a -P -u -z --stats root@devdeb2:/srv /mnt/sdb2

rsync can also be used with a User/Password respectively a shared secret authentification without ssh.

On the target machine install and start rsync as a daemon.

root@debdev ~# apt-get install rsync
root@debdev ~# systemctl enable rsync

Open respectively create file /etc/rsyncd.conf and add a “Module”. In this example customized monit files. Explanation: A module exports a directory by a symblic name. uid and gid are the credentials under which the rsync process runs. Means the user needs access to the path defined in the module.

[monit]
path = /etc/monit/conf.d
comment = Monit
uid = root
gid = root
auth users = monit-replication
secrets file = /etc/rsyncd.secrets

/etc/rsyncd.secrets

monit-replication:MySecretPassword


On your source machine. Create also a /etc/rsyncd.secrets file with just the password as content.

MySecretPassword

Set permissions

root@debdev2 ~# chown root:root /etc/rsyncd.secrets
root@debdev2 ~# chmod 400 /etc/rsyncd.secrets

To run rsync without prompting for the password specify the –password-file=/etc/rsyncd.secrets parameter or set the Environment variable RSYNC_PASSWORD

root@debdev2 ~# export RSYNC_PASSWORD=MySecretPassword

Check folder access

root@debdev2 ~# rsync --password-file=/etc/rsyncd.secrets rsync://monit-replication@debdev/monit

And get the folder

root@debdev2 ~# rsync -a -P -u -z --stats --password-file=/etc/rsyncd.secrets rsync://monit-replication@debdev/monit /tmp

Filters. Note: Default is to includes all. This example copies all pdf files. Importent is to set the include before the exclude filter because the first match determines if a file is copied or not.

root@debdev2 ~# rsync -a -P -u -z --stats --include '*.pdf' --exclude '*' --password-file=/etc/rsyncd.secrets rsync://monit-replication@debdev/monit /tmp
--include '*.pdf' --exclude '*' 

To exclude more the one folders use the exclude switch multiple times

michael@debdev ~# rsync -a -exclude .cache -exclude Downloads ~/MyStuff michael@devdeb2:/home/michael/MyStuff

Michael