diff --git a/tbku.txt b/tbku.txt
index cf5e111..5295316 100644
--- a/tbku.txt
+++ b/tbku.txt
@@ -86,15 +86,28 @@
string of text that includes the machine name, system type, OS type,
date, *and* the so-called *set name*. The "set name" is nothing
more than the suffix of the name of the fileset used to produce the
- tarball, in this case, ``homedirs``. Additionally, you'll also find
- a log of the backup and "dot files" that tell you when the backup
- began and when it ended. Here's part of what you might see if you
- did an ``ls -al /bku``::
+ tarball, in this case, ``homedirs``.
- Mar 19 05:46 .mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs-begin
- Mar 19 05:47 .mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs-end
- Mar 19 05:46 mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs-20080319.tar.gz
- Mar 19 05:46 mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs.log
+ Additionally, you'll also find a log of the backup and "dot files"
+ that tell you when the backup began and when it ended. Here's part
+ of what you might see if you did an ``ls -a /bku``::
+
+ .mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs-20080319-begin
+ .mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs-20080319-end
+ mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs-20080319.tar.gz
+ mach.fake.org-FreeBSD-6.3-STABLE-i386-homedirs-20080319.log
+
+ The "dot files" don't actually contain any information, but their
+ date/time stamps (you can see this with ``ls -al /bku``) will tell
+ you when the backup began and ended.
+
+ The log file contains a list of all the files that actually
+ made it into the tarball. The log file also captures *the
+ errors* encountered during a backup. This means that ``tbku``
+ is generally pretty quiet during a backup run. It scribbles
+ any complaints it has into the log. So... you should check
+ your logs regularly to make sure everything is working as
+ expected.
You can create as many different filesets as you like (for as many
different kinds of backups as you need). So, for example, you may
@@ -185,12 +198,36 @@
happens under one of several circumstances:
1) You ran ``tbku`` without arguments, but there are no
- "auto" file sets defined.
+ "auto" filesets defined.
- 2) You ran ``tbku`` with arguments, but no file sets with
+ 2) You ran ``tbku`` with arguments, but no filesets with
matching set names were found.
- 3) There are no file sets at all.
+ 3) There are no filesets at all.
+
+ **Autodeletion Of Old Backups**
+
+ As shipped, ``tbku`` uniquely identifies each backup set based on
+ machine name, OS, CPU architecture, set name, and, most importantly,
+ date. If you've set it up to run as a cron job, over time you'll
+ accumulate lots of older copies of backups. That's because each new
+ day, the backup file name will change (since it include the date).
+
+ If you don't like this default behavior, change the ``TBKUDEL``
+ environment variable to be "YES". It must be *exactly* this string,
+ all in upper case. Anything else will cause ``tbku`` to *not*
+ autodelete old backups. This is intentional, to make it hard to
+ accidentally enable this feature.
+
+ Enabling this feature forces ``tbku`` to delete all older files
+ associated with the selected set name. This includes the start/stop
+ "dot" files, the log, and the backup tarball itself. In effect,
+ this option forces ``tbku`` to only keep the most recent backup of
+ each backup set.
+
+ *Use this option with caution!* If you only keep the most recent
+ copy of your backups in your backup directory, you may never be able
+ to get to changes made days, weeks, or months prior.
**IMAGING WITH tbku**
@@ -233,14 +270,15 @@
corresponding environment variable.
- ================= =============================== ======================
+ ================= =============================== =========================
**Env. Variable** **Default Value** **Meaning**
- ----------------- ------------------------------- ----------------------
+ ----------------- ------------------------------- -------------------------
+ TBKUDEL NO YES -> Delete old backups
TBKUDIR /bku Where to write backups
TBKUNAME $MACHINE-$OSTYPE-$OSREV-$HWTYPE Tarball base name
TBKUSETS $HOME/tbku Filesets found here
TBKUTAPE /dev/sa0 Tape device (or file)
- ================= =============================== ======================
+ ================= =============================== =========================
Examples::
@@ -253,12 +291,14 @@
export TBKUTAPE-/tmp/faketape # Tape backups actually written to *file*
+ export TBKUDEL="YES" # Autodelete old backups when starting a set
+
**OTHER**
``tbku`` was originally designed for use by experienced
systems administrators and users. As such, it does little
- or no error checking. If you define backup or file set
+ or no error checking. If you define backup or fileset
directories that are non-existent, for instance, you will
get strange behavior. ``tbku`` *will* try to create the
backup directory you've specified if it does not already
@@ -317,4 +357,4 @@
http://docutils.sourceforge.net/rst.html
-``$Id: tbku.txt,v 1.107 2008/03/19 20:02:36 tundra Exp $``
+``$Id: tbku.txt,v 1.108 2008/03/19 21:42:32 tundra Exp $``