Use rsync copy multiple directories to the same location; keep tree

Question

I'm using a Time Machine like backup script, that creates a partial backup to an external drive using hard links:

#!/bin/bash

date=`date "+%Y-%m-%dT%H-%M-%S"`
backup=/mnt/backup
targets="/ /data/seafile /boot /boot/efi"

mkdir -p $backup/logs 

rsync -a \
    --stats \
    --partial \
    -h \
    -H \
    -A \
    -X \
    -x \
    --log-file=$backup/logs/$date.log \
    --exclude='/media/**' --exclude='/mnt/**' --exclude='/proc/**' --exclude='/sys/**' --exclude='/tmp/**' --exclude='/run/**' --exclude='/dev/**' \
    $targets \
    --link-dest=$backup/latest \
    $backup/incomplete_$date \
    && mv $backup/incomplete_$date $backup/$date \
    && rm -f $backup/latest \
    && ln -s $backup/$date $backup/latest

Result:

/mnt/backup/
├── 2016-05-24T16-33-08
...
├── 2016-12-01T22-04-25
├── 2016-12-05T20-29-52
├── latest -> /mnt/backup/2016-12-05T20-29-52
├── logs
└── lost+found

This worked fine so far, until I started to use LVM and split up my data to different mount points. Now the contents of these backups look like this:

/mnt/backup/latest
├── bin
├── boot
├── data
...
├── efi
...
├── seafile
...

What I actually intented is that rsync copies every item of the list / /data/seafile /boot /boot/efi to the proper location in the hierarchy, so for e.g. the folders should end up like this:

/mnt/backup/latest
├── boot
│   ├── efi
...
├── data
│   └── seafile

The reason why I have to specify every target is the -x option. This stops rsync from crossing a file system border during the recursion. A "simple" solution would be to:

• remove the -x flag
• specify only / as target

But this gives me some additional disadvantages. For example I would have to exclude any unwanted mount point with an additional --exclude='/.../**' tag. For now these aren't too much, but I'd rather like to have an opt-in instead of an opt-out solution.

Answer 1

You should be able to get the effect you want with the -R (or --relative) flag. The reproduces the full path of the source in the destination, eg rsync -aR /a/b/c /dest will create a directory /dest/a/b/c.

Your --link-dest should still work but only once you have done a first new copy, so you may prefer to move the directories around in your last backup to match the new hierarchy or not all the hard links will be made.