Colas.Nahaboo.net / software / rsync-incr

User Manual

rsync-incr v1.0 is a linux wrapper shell (bash) script around rsync to perform automated, unattended, incremental, disk to disk backups, automatically removing old backups to make room for new ones. It produces standard mirror copies browsable and restorable without specific tools.

rsync-incr will create destdir as a perfect mirror, and save in destdir.past a directory per run with copies of changed files old versions. These N (at most) directories of old versions of changed files are named by their dates in the form destdir.past/YYYY-MM-DD.HHhMN-SIZEm
e.g: /backups/home.past/2005-01-24.04h23-122m
Date of last backup is in the contents of file destdir.past/LAST_DATE. No need to apend trailing / to source and destination.
Dest must be on the local machine (maybe NFS-mounted), source can be on a remote machine via the syntax host:dir
SIZE in name is the disk space taken that this backup, in megabytes, before an optional compression via --cbf, to help you find the good value of Nm (e.g: the max of past SIZEs), as this size is hard to find in --snap mode SIZE is rounded to upper bound: 0m means 0 bytes, 2m less than 2m

This a simple script, making backups usables by standard rsync (no need for a dedicated restore script). It has 2 basic modes of operation:

• default: make a perfect copy, of all hard links, devices, sparse files, and just stores in dirs the previous versions of only the changed files. This makes it easy to find the different states a files went through, but make it harder to get a perfect snapshot of what was the full state N days before.
• --snap: makes full snapshots of what the source was like at backup times as described in Mike Rubel article It is easier to get to full snapshots of previous states, and should run faster than the default.

Options are pased to rsync, but must be a single word parts (use --rsh=ssh, not -e ssh)
e.g: rsync-incr -z --bwlimit=12 --rsh=ssh server:/home/me /backups/me
(this will create an perfect backup in /backups/me and a series of previous versions as dirs like /backups/me.past/2004-10-26.04:40:20-234 ...) rsync-incr sets rsync options: -HSax --delete --force

Special non-rsync options:

• --nohl do not use the -H / --hard-links option (do not preserve hard links), faster if you do not need to preserve hard links.
• --cbf compresses (gzip -r) all backuped files (will not compress files with hard links)
• --snap old backups are full snapshots of previous stats, as in Mike Rubel article but this do not preserve hard links
• --grem global remove: with m appended to N, (i.e., N given as a number of megabytes), will remove oldest backups globally on the filesystem (otherwise space-making on a small backup could be wiped out because of bigger backups).
  You should place a list (one per line) of all the absolute paths of LAST_DATE files on the system in the env variable RSYNCINCR_LASTDATES, for instance by a statement:
  export RSYNCINCR_LASTDATES=
  otherwise a global find will be used, which can be very slow. It will only remove backups on same filesystem as destdir, so you can list all LAST_DATE paths on all disks.
• --pbsm=P Previous Backups Space Margin: reserve space before backup for at least the max size of previous backups + P% (P default to 10). If P ends with "m" (like 7m) it is taken as P megabytes to add rather as a percentage.

Rsync errors are propagated (the script exits with rsync exit status), except for the error #24 which is trapped, as this error can happen on backups of live systems (being modified while backuped)