Rsync: backups and hard links

JosephS · 07-13-2011, 01:37 PM

I am using rsync for incremental backups. I am backing up to a second hard drive on my computer. When I check the individual backup directories (backup.0 through backup.4) with du -hs they each show 12G; when I check the parent directory squeeze it shows 15G. Over 4 backups I have added 3G. I haven't made very much for changes to directories I'm backing up and am using hard links. I have included some info below. Maybe someone can show me what is wrong.

Quote:

Backup script:
#!/bin/bash
mount /mnt/backup
cd /mnt/backup/squeeze/
rm -rf backup.7
mv backup.6 backup.7
mv backup.5 backup.6
mv backup.4 backup.5
mv backup.3 backup.4
mv backup.2 backup.3
mv backup.1 backup.2
mv backup.0 backup.1
cd /
rsync -am --delete-after --filter="merge /root/scripts/filter-rule" --delete-excluded \
--link-dest=/mnt/backup/squeeze/backup.1 \
/ /mnt/backup/squeeze/backup.0
umount /mnt/backup

Quote:

filter-rule:
- /home/joe/downloads/
- /home/joe/.local/share/Trash/
+ /home/
+ /etc/
+ /root/
+ /boot/
+ /usr/
+ /usr/local/
- /usr/*
- /*

arizonagroovejet · 07-13-2011, 02:03 PM

Put output, commands, scripts and such in CODE tags. It makes your post easier to read. (CODE tags can be added using the button marked # when composing a post)

I don't think I entirely understand your description of the problem - are you saying that the source directory contains hardlinks and has a total size of 12GB but the destination directory ends up containing 15GB? If so, look at the -H option.

JosephS · 07-13-2011, 09:39 PM

Sorry about the confusion. I am backing up from drive A to B. I am backing up the directories in the filter rule under / to /mnt/backup/squeeze/backup.0. There are no hard links in the source directory. The hard links are on the destination directory. With the --link-dest=/mnt/backup/squeeze/backup.1 rsync hard links unchanged files in backup.0/ to backup.1/ and copies new or changed files from the source directories under / to backup.0/
I don't make many changes so with the hard links I can't see why there is so much extra space taken. If most of the files under /mnt/backup/squeeze/ are hark linked (backup.0 through backup.4) and show each 12G why is /mnt/backup/squeeze/ 15G?

Quote:

Here is quote from an article:
--link-dest this is a neat way to make full backups of your computers without losing much space. rsync links unchanged files to the previous backup (using hard-links, see below if you don’t know hard-links) and only claims space for changed files. This only works if you have a backup at hand, otherwise you have to make at least one backup beforehand.