mjhjmtu

I'm going to be using rsync to sync an old home folder onto a backup drive. I'm thinking of using rsync as root. Is there a way to avoid changing the ownership of the files etc I copy?

You can use the -o and -g options. From the rsync manual (man rsync):

-o, --owner preserve owner (super-user only)

-g, --group preserve group

Going one step further, an option commonly used with rsync is the -a/--archive option. This option implies -rlptgoD, which are the following options:

-r, --recursive recurse into directories

-l, --links copy symlinks as symlinks

-p, --perms preserve permissions

-t, --times preserve modification times

-D same as --devices --specials (preserve device files, preserve special files)

I use the following command line to preserve 'everything', file content, ownership and permissions of files, directories, symbolic links etc. This way I have been able to copy a system to a new drive and make it work in another computer. OK, I had to fix the bootloader too, but it works well with copying of the file content, ownership and permissions.

• Please notice the trailing slash on the source directory, and read about it in man rsync.

 rsync -avz foo:src/bar/ /data/tmp

 A trailing slash on the source changes this behavior to avoid creating
 an additional directory level at the destination. You can think of a
 trailing / on a source as meaning "copy the contents of this directory"
 as opposed to "copy the directory by name", but in both cases the
 attributes of the containing directory are transferred to the contain‐
 ing directory on the destination. In other words, each of the follow‐
 ing commands copies the files in the same way, including their setting
 of the attributes of /dest/foo:

 rsync -av /src/foo /dest
 rsync -av /src/foo/ /dest/foo

 Note also that host and module references don’t require a trailing
 slash to copy the contents of the default directory. For example, both
 of these copy the remote directory’s contents into "/dest":

 rsync -av host: /dest
 rsync -av host::module /dest

 You can also use rsync in local-only mode, where both the source and
 destination don’t have a ’:’ in the name. In this case it behaves like
 an improved copy command.

• 
  

  -n, start with a 'dry run', to check that things look correct.

  
  
  

  sudo rsync -Havn source/ target
  

  
  


• 
  

  Remove the option (-n) and let rsync do its job.

  
  
  

  sudo rsync -Hav source/ target
  

  
  

It will check if each directory/file in the target exists and is up to date, and only copy what needs to be updated (in a backup scenario).

• 
  -H keeps track of hard links (which save drive space), but makes the copy process slower (the reason that it is not included in -a
  


• 
  -a is the standard archive option for backup purposes, which preserves 'everything' about the files in the file system (except hard links).


• 
  -v is the classic verbose option, which prints all files that are to be copied. There are other options to monitor the progress, that you may like better. You may prefer to turn off verbosity, but it is good in the early stages to check that things work are expected.