ccollect/doc/ccollect.text

ccollect - Installing, Configuring and Using
============================================
Nico Schottelius <nico-linux-ccollect__@__schottelius.org>
0.3.1, for ccollect 0.3.1, Initial Version from 2005-01-13
:Author Initials: NS

(pseudo) incremental backup
with different exclude lists
using hardlinks and `rsync`

Introduction
------------
ccollect is a backup utitily written in the sh-scripting language.
It does not depend on a specific shell, only `/bin/sh` needs to be
bourne shell compatibel (like 'dash', 'ksh', 'zsh', 'bash', ...).


Why you can only backup TO localhost
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
While thinking about the design of ccollect, I thought about enabling
backup to *remote* hosts. Though this sounds like a nice feature
('Backup my notebook to the server now.'), it is in my opinion a
bad idea to backup to a remote host, because you have to open
security at your backup host. Think of the following situation: You backup
your farm of webservers *to* a backup host somewhere else. One of
your webservers gets compromised, then your backup server will be compromised,
too. Think of it the other way round: The backup server (now behind a
firewall using NAT and strong firewall rules) connects to the
webservers and pulls the data to it. If someone gets access to the
webserver, the person will perhaps not even see your machine. If
he/she sees that there are connections from a host to the compromised
machine, he/she will not be able to login to the backup machine.
All other backups are still secure.


Requirements
------------

Installing ccollect
~~~~~~~~~~~~~~~~~~~

For the installation, you need at least

  - either `cp` and `chmod` or `install`
  - for more comfort: `make`
  - for rebuilding the generated documentation: additionally `asciidoc`


Using ccollect
~~~~~~~~~~~~~~
.Running ccollect requires the following tools installed:
   - `bc`
   - `cp` with support for hard links ('cp -al')
   - `date`
   - `rsync`
   - `ssh` (if you want to use rsync over ssh, which is recommened for security)


Installing
----------
Either type 'make install' or simply copy it to a directory in your
$PATH and execute 'chmod *0755* /path/to/ccollect.sh'.


Configuring
-----------

Runtime options
~~~~~~~~~~~~~~~
`ccollect` looks for its configuration in '/etc/ccollect' or, if set, in
the directory specified by the variable '$CCOLLECT_CONF'
(use 'CCOLLECT_CONF=/your/config/dir ccollect.sh' on the shell).

When you start `ccollect`, you have either to specify which intervall
to backup (daily, weekly, yearly; you can specify the names yourself, see below).

The intervall is used to specify how many backups to keep.

There are also some self explaining parameters you can pass to ccollect, simply use
"ccollect.sh --help" for info.


General configuration
~~~~~~~~~~~~~~~~~~~~~
The general configuration can be found below $CCOLLECT_CONF/defaults or
/etc/ccollect/defaults. All options specified here are generally valid for
all source definitions. Though the values can be overwritten in the source
configuration.

All configuration entries are plain-text (use UTF-8 if you use
non ASCII characters) files.


Intervall definition
^^^^^^^^^^^^^^^^^^^^
The intervall definition can be found below
'$CCOLLECT_CONF/defaults/intervalls/' or '/etc/ccollect/defaults/intervalls'. 
Every file below this directory specifies an intervall. The name of the file is the
name of the intervall: `intervalls/'<intervall name>'`.

The content of this file should be a single line containing a number.
This number defines how many versions of this intervall to keep.

Example:
-------------------------------------------------------------------------
   [10:23] zaphodbeeblebrox:ccollect-0.2% ls -l conf/defaults/intervalls/
   insgesamt 12
   -rw-r--r--  1 nico users 3 2005-12-08 10:24 daily
   -rw-r--r--  1 nico users 3 2005-12-08 11:36 monthly
   -rw-r--r--  1 nico users 2 2005-12-08 11:36 weekly
   [10:23] zaphodbeeblebrox:ccollect-0.2% cat conf/defaults/intervalls/*
   28
   12
   4
--------------------------------------------------------------------------------
This means to keep 28 daily backups, 12 monthly backups and 4 weekly.

General pre- and post-execution
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If you add '$CCOLLECT_CONF/defaults/`pre_exec`' or
'/etc/ccollect/defaults/`pre_exec`' (same with `post_exec`), `ccollect`
will start `pre_exec` before the whole backup process and
`post_exec` after backup of all sources is done.

Example:
-------------------------------------------------------------------------
[13:00] hydrogenium:~# mkdir -p /etc/ccollect/defaults/
[13:00] hydrogenium:~# echo '!/bin/sh' > /etc/ccollect/defaults/pre_exec
[13:01] hydrogenium:~# echo '' > /etc/ccollect/defaults/pre_exec 
[13:01] hydrogenium:~# echo '!/bin/sh' > /etc/ccollect/defaults/pre_exec
[13:01] hydrogenium:~# echo '' >> /etc/ccollect/defaults/pre_exec       
[13:01] hydrogenium:~# echo 'df -h' >> /etc/ccollect/defaults/pre_exec
[13:01] hydrogenium:~# chmod 0755 /etc/ccollect/defaults/pre_exec
[13:01] hydrogenium:~# cp /etc/ccollect/defaults/pre_exec /etc/ccollect/defaults/post_exec
-------------------------------------------------------------------------

Source configuration
~~~~~~~~~~~~~~~~~~~~
Each source configuration exists below '$CCOLLECT_CONF/sources/$name' or
'/etc/ccollect/sources/$name'.

The name you choose for the subdirectory describes the source.

Each source has at least the following files:

   - `source`       (a text file containing the `rsync` compatible path to backup)
   - `destination`  (a link to the directory we should backup to)

Additionally a source may have the following files:

   - `verbose`       whether to be verbose (passes -v to `rsync`)
   - `very_verbose`  be very verbose (-v also for `mkdir`, `cp`, `rm`)
   - `summary`       create a transfer summary when `rsync` finished

   - `exclude`       exclude list for `rsync`. newline ('\n') seperated list.
   - `rsync_options' extra options to pass to `rsync`

   - `pre_exec`      program to execute before backuping this source
   - `post_exec`     program to execute after backuping this source

Example:
--------------------------------------------------------------------------------
   [10:47] zaphodbeeblebrox:ccollect-0.2% ls -l  conf/sources/testsource2
   insgesamt 12
   lrwxrwxrwx  1 nico users   20 2005-11-17 16:44 destination -> /home/nico/backupdir
   -rw-r--r--  1 nico users   62 2005-12-07 17:43 exclude
   drwxr-xr-x  2 nico users 4096 2005-12-07 17:38 intervalls
   -rw-r--r--  1 nico users   15 2005-11-17 16:44 source
   [10:47] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/exclude 
   openvpn-2.0.1.tar.gz
   nicht_reinnehmen
   etwas mit leerzeichenli
   [10:47] zaphodbeeblebrox:ccollect-0.2% ls -l  conf/sources/testsource2/intervalls
   insgesamt 4
   -rw-r--r--  1 nico users 2 2005-12-07 17:38 daily
   [10:48] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/intervalls/daily 
   5
   [10:48] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/source 
   /home/nico/vpn
--------------------------------------------------------------------------------

Detailled description of "source"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
`source` describes a `rsync` compatible source (one line only).
 
For instance 'backup_user@foreign_host:/home/server/video'.
To use the `rsync` protocol without the `ssh`-tunnel, use
'rsync::USER@HOST/SRC'. For more information have a look at `rsync`(1).
 
Detailled description of "verbose"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
`verbose` tells `ccollect` that the log should contain verbose messages.

If this file exists in the source specification *-v* will be passed to `rsync`.

Example:
--------------------------------------------------------------------------------
   [11:35] zaphodbeeblebrox:ccollect-0.2% touch conf/sources/testsource1/verbose
--------------------------------------------------------------------------------

Detailled description of "very_verbose"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
`very_verbose` tells `ccollect` that it should log very verbose.

If this file exists in the source specification *-v* will be passed to
`rsync`, `cp`, `rm` and `mkdir`.

Example:
--------------------------------------------------------------------------------
   [23:67] nohost:~% touch conf/sources/testsource1/very_verbose
--------------------------------------------------------------------------------

Detailled description of "summary"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If you create the file `summary` below the source definition,
`ccollect` will present you with a nice summary at the end.

-------------------------------------------------------------------------------
backup:~# touch /etc/ccollect/sources/root/summary
backup:~# ccollect.sh werktags root
==> ccollect.sh: Beginning backup using intervall werktags <==
[root] Beginning to backup this source ...
[root] Currently 3 backup(s) exist, total keeping 50 backup(s).
[root] Beginning to backup, this may take some time...
[root] Hard linking...
[root] Transferring files...
[root] 
[root] Number of files: 84183
[root] Number of files transferred: 32
[root] Total file size: 26234080536 bytes
[root] Total transferred file size: 9988252 bytes
[root] Literal data: 9988252 bytes
[root] Matched data: 0 bytes
[root] File list size: 3016771
[root] File list generation time: 1.786 seconds
[root] File list transfer time: 0.000 seconds
[root] Total bytes sent: 13009119
[root] Total bytes received: 2152
[root] 
[root] sent 13009119 bytes  received 2152 bytes  2891393.56 bytes/sec
[root] total size is 26234080536  speedup is 2016.26
[root] Successfully finished backup.
==> Finished ccollect.sh <==
-------------------------------------------------------------------------------

You could also combine it with `verbose` or `very_verbose`, but they
already print some statistics (but not all / the same as presented by
`summary`).


Detailled description of "exclude"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
`exclude` specifies a list of paths to exclude. The entries are new line (\n)
seperated.

Example:
--------------------------------------------------------------------------------
   [11:35] zaphodbeeblebrox:ccollect-0.2% cat conf/sources/testsource2/exclude 
   openvpn-2.0.1.tar.gz
   nicht_reinnehmen
   etwas mit leerzeichenli
   something with spaces is not a problem
--------------------------------------------------------------------------------


Detailled description of "destination"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
`destination` must be a link to the destination directory.

Example:
--------------------------------------------------------------------------------
   [11:36] zaphodbeeblebrox:ccollect-0.2% ls -l conf/sources/testsource2/destination 
   lrwxrwxrwx  1 nico users 20 2005-11-17 16:44 conf/sources/testsource2/destination -> /home/nico/backupdir
--------------------------------------------------------------------------------


Detailled description of "intervalls/"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
When you create a subdirectory `intervalls/` within your source configuration
directory, you can specify individiual intervalls for this specific source.
Each file below this directory describes an intervall.

Example:
--------------------------------------------------------------------------------
   [11:37] zaphodbeeblebrox:ccollect-0.2% ls -l conf/sources/testsource2/intervalls/      
   insgesamt 8
   -rw-r--r--  1 nico users 2 2005-12-07 17:38 daily
   -rw-r--r--  1 nico users 3 2005-12-14 11:33 yearly
   [11:37] zaphodbeeblebrox:ccollect-0.2% cat  conf/sources/testsource2/intervalls/*
   5
   20
--------------------------------------------------------------------------------

Detailled description of "rsync_options"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

When you create the file `rsync_options` below your source configuration,
all the parameters found in this file will be passed to rsync. This
way you can pass additional options to rsync. For instance you can tell rsync
to show progress ("--progress") or which -password-file ("--password-file")
to use for automatic backup over the rsync-protocol.

Example:
--------------------------------------------------------------------------------
   [23:42] hydrogenium:ccollect-0.2% cat conf/sources/test_rsync/rsync_options
   --password-file=/home/user/backup/protected_password_file
--------------------------------------------------------------------------------

Detailled description of "pre_exec" and "post_exec"
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

When you create `pre_exec` and / or `post_exec` below your source
configuration, `ccollect` will execute this command before,
respective after doing the backup for *this specific* source.
If you want to have pre-/post-exec before and after *all*
backups, see above for general configuration.

Example:
--------------------------------------------------------------------------------
[13:09] hydrogenium:ccollect-0.3% cat conf/sources/with_exec/pre_exec 
#!/bin/sh

# Show whats free before
df -h
[13:09] hydrogenium:ccollect-0.3% cat conf/sources/with_exec/post_exec 
#!/bin/sh

# Show whats free after
df -h
--------------------------------------------------------------------------------

Hints
-----

Using rsync protocol without ssh
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When you have a computer with little computing power, it may be useful to use
rsync without ssh, directly using the rsync protocol
(specify 'user@host::share' in `source`). You may wish to use
`rsync_options` to specify a password file to use for automatic backup.


Example:
--------------------------------------------------------------------------------
backup:~# cat /etc/ccollect/sources/sample.backup.host.org/source         
backup@webserver::backup-share

backup:~# cat /etc/ccollect/sources/sample.backup.host.org/rsync_options 
--password-file=/etc/ccollect/sources/sample.backup.host.org/rsync_password

backup:~# cat /etc/ccollect/sources/sample.backup.host.org/rsync_password 
this_is_the_rsync_password
--------------------------------------------------------------------------------
This hint was reported by Daniel Aubry.


Not-excluding top-level directories
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When you exclude "/proc" or "/mnt" from your backup, you may run into
trouble when you restore your backup. When you use "/proc/\*" or "/mnt/\*"
instead `ccollect` will backup empty directories.

[NOTE]
===========================================
When those directories contain hidden files
(those beginning with a dot (*.*)),
they will still be transferred!
===========================================
This hint was reported by Marcus Wagner.


Re-using already created rsync-backups
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you used `rsync` directly before you use `ccollect`, you can
use this old backup as initial backup for `ccollect`: You
simply move it into a subdirectory named "'intervall'.0".

Example:
-------------------------------------------------------------------------------
backup:/home/backup/web1# ls
bin   dev  etc   initrd  lost+found  mnt  root  srv  usr  vmlinuz
boot  doc  home  lib     media       opt  sbin  tmp  var  vmlinuz.old

backup:/home/backup/web1# mkdir daily.0

# ignore error about copying to itself
backup:/home/backup/web1# mv * daily.0 2>/dev/null

backup:/home/backup/web1# ls
daily.0
-------------------------------------------------------------------------------
Now you could use /home/backup/web1 as the `destination` for the backup.

[NOTE]
===============================================================================
Do *not* name the first backup something like "daily.initial", but use
the "*0*" (or some very low number, at least lower than the current year)
as extension. `ccollect` uses `sort` to find the latest backup. `ccollect`
itself uses 'intervall.YEAR-MONTH-DAY-HOUR:MINUTE.PID'. This notation will
*always* be before "daily.initial", as numbers are earlier in the list
which is produced by `sort`. So, if you have a directory named "daily.initial",
`ccollect` will always diff against this backup and transfer and delete
files which where deleted in previous backups. This means you simply
waste resources, but your backup will be complete.
===============================================================================


Using pre_/post_exec
~~~~~~~~~~~~~~~~~~~~
Your pre_/post_exec script does not need to be a script, you can also
use a link to

   - an existing program
   - an already written script

The only requirement is that it is executable.

F.A.Q.
------

What happens, if one backup is broken or empty?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Let us assume, that one backup failed (connection broke or hard disk had
some failures). So we've one backup in our history, which is incomplete.

The next time you use `ccollect`, it will transfer the missing files


When backing up from localhost the destination is also included. Is this a bug?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

No. `ccollect` passes your source definition directly to `rsync`. It
does not try to analyze it. So it actually does not know if a source
comes from local harddisk or from a remote server. And it does not want
to. When you backup from the local harddisk (which is perhaps not
even a good idea when thinking of security) add the `destination`
to 'source/exclude'. (Daniel Aubry reported this problem)


Why does ccollect say "Permission denied" with my pre-/postexec script?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The most common error is to not give your script the correct
permissions. Try `chmod 0755 '/etc/ccollect/sources/yoursource/*_exec'`.


Examples
--------

A backup host configuration from scratch
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

--------------------------------------------------------------------------------
srwali01:~# mkdir /etc/ccollect
srwali01:~# mkdir -p /etc/ccollect/defaults/intervalls/
srwali01:~# echo 28 > /etc/ccollect/defaults/intervalls/taeglich
srwali01:~# echo 52 > /etc/ccollect/defaults/intervalls/woechentlich
srwali01:~# cd /etc/ccollect/
srwali01:/etc/ccollect# mkdir sources
srwali01:/etc/ccollect# cd sources/
srwali01:/etc/ccollect/sources# ls
srwali01:/etc/ccollect/sources# mkdir local-root
srwali01:/etc/ccollect/sources# cd local-root/
srwali01:/etc/ccollect/sources/local-root# echo / > source
srwali01:/etc/ccollect/sources/local-root# cat > exclude << EOF
> /proc
> /sys
> /mnt
> EOF
srwali01:/etc/ccollect/sources/local-root# ln -s /mnt/hdbackup/local-root destination
srwali01:/etc/ccollect/sources/local-root# mkdir /mnt/hdbackup/local-root
srwali01:/etc/ccollect/sources/local-root# ccollect.sh taeglich local-root
/o> ccollect.sh: Beginning backup using intervall taeglich
/=> Beginning to backup "local-root" ...
|-> 0 backup(s) already exist, keeping 28 backup(s).
--------------------------------------------------------------------------------

After that, I added some more sources:
--------------------------------------------------------------------------------
srwali01:~# cd /etc/ccollect/sources
srwali01:/etc/ccollect/sources# mkdir windos-wl6
srwali01:/etc/ccollect/sources# cd windos-wl6/
srwali01:/etc/ccollect/sources/windos-wl6# echo /mnt/win/SYS/WL6 > source
srwali01:/etc/ccollect/sources/windos-wl6# ln -s /mnt/hdbackup/wl6 destination
srwali01:/etc/ccollect/sources/windos-wl6# mkdir /mnt/hdbackup/wl6
srwali01:/etc/ccollect/sources/windos-wl6# cd ..
srwali01:/etc/ccollect/sources# mkdir windos-daten
srwali01:/etc/ccollect/sources/windos-daten# echo /mnt/win/Daten > source
srwali01:/etc/ccollect/sources/windos-daten# ln -s /mnt/hdbackup/windos-daten destination
srwali01:/etc/ccollect/sources/windos-daten# mkdir /mnt/hdbackup/windos-daten

# Now add some remote source
srwali01:/etc/ccollect/sources/windos-daten# cd ..
srwali01:/etc/ccollect/sources# mkdir srwali03
srwali01:/etc/ccollect/sources# cd srwali03/
srwali01:/etc/ccollect/sources/srwali03# cat > exclude << EOF
> /proc
> /sys
> /mnt
> /home
> EOF
srwali01:/etc/ccollect/sources/srwali03# echo 'root@10.103.2.3:/' > source
srwali01:/etc/ccollect/sources/srwali03# ln -s /mnt/hdbackup/srwali03 destination
srwali01:/etc/ccollect/sources/srwali03# mkdir /mnt/hdbackup/srwali03
--------------------------------------------------------------------------------

Using hard-links requires less disk space
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-------------------------------------------------------------------------
[10:53] srsyg01:sources% du -sh ~/backupdir 
4.6M    /home/nico/backupdir
[10:53] srsyg01:sources% du -sh ~/backupdir/*
4.1M    /home/nico/backupdir/daily.2005-12-08-10:52.28456
4.1M    /home/nico/backupdir/daily.2005-12-08-10:53.28484
4.1M    /home/nico/backupdir/daily.2005-12-08-10:53.28507
4.1M    /home/nico/backupdir/daily.2005-12-08-10:53.28531
4.1M    /home/nico/backupdir/daily.2005-12-08-10:53.28554
4.1M    /home/nico/backupdir/daily.2005-12-08-10:53.28577

srwali01:/etc/ccollect/sources# du -sh /mnt/hdbackup/wl6/         
186M    /mnt/hdbackup/wl6/
srwali01:/etc/ccollect/sources# du -sh /mnt/hdbackup/wl6/*
147M    /mnt/hdbackup/wl6/taeglich.2005-12-08-14:42.312
147M    /mnt/hdbackup/wl6/taeglich.2005-12-08-14:45.588
-------------------------------------------------------------------------