Datbkr Tape Backup system
Dave Cinege <dcinege at psychosis.com>
FTP site
News:
2003-09-17 Datbrk is no longer maintained. As requested I've posted my last version at the ftp site.
2003-06-22 Datbrk is no longer maintained. I'm still using it, but am getting ready it move to something other then tape for backup. (DVD-R?) If you can recommend better backup software to ME please do so.
2001-02-17 I have a new version of datbkr that I've been using, better designed for non-DAT drives. (I now use an Ecrix) It can keep multiple archives per tape, and stores the archive index right after the data archive instead of requiring a partition.. It's not quite ready to be released. Please send me mail complaining, to motivate me to finish it. : )
Datbkr version 1999030301 released. Fixes a minor bug in the host name check. Changed some bash centric things to make the script more portable.
Datbkr version 1998100401 released. Fixes a minor bug in the log file timestamp. Was using %m(month) instead of %M(minute). Opps!
Grab the new version of tarblocks.
#1 I put the wrong source file here...it had a display bug. : P
#2 Special files (/dev/) were screwing up the offsets. They stor major,minor where the size normally is. Now I only check size for regular files.
FAQ
What is Datbkr?
Datbkr is the end result of the evolution of some scripts and programs
that I created over several months to handle my back-up needs.
What makes Datbkr special?
Datbkr is very light weigth, and simple to use. Besides this it is
designed to provide seemless backup's over an encrypted ssh (secure shell)
link.
What does it work with?
Datbkr itself is comprised of a multicall, tar based, sh script, and a
small program called tarblocks. It was developed on Debian Linux 2.0
w/bash 2.0, but should work with most any unix with GNU utils and sh shell.
What tape drives does it work with?
It has been designed to work with partitionable dat drives.
The partition is used to keep the tape index and back-up log
report. You also must have an mt command that can handle this (mt-st)
How does it work?
It is all very basic..check for a tape, ask to proceed, ssh into dat server,
etc etc. The script is very well done and seemless, with command line
parameters to override defaults. Right now it is made to keep only one
archive per tape.
Do I need this?
It works very well for simple large filesytem backups on either your local
or remote machines. It is geared towards one shot server backup's, not
incremental or multivolume backups.
Why do I want this over my own tar script? It shows progress in MB written. It can estimate archive size. It creates nice backup reports that are mailed to you. It is a sh script that can be customized as needed. It creates an output file with block listings for quick single file retrieval. Setting up seemless ssh backups with logging that can be cron'ed is a real motherfucker.
Installation and set up:
Download the following -
datbkr
mt-st
tarblocks
compile mt-st (see readme)
compile tarblocks (gcc -o tarblocks tarblocks.c; strip tarblocks)
Copy datbkr, mt-st, and tarblocks to /usr/local/bin/ Symlink datbkr as datbkr-mt and datbkr-rshtar (ln -s datbkr datbkr-mt; ln -s datbkr datbkr-rshtar)
Edit datbkr. There is a user configuation section at the top of the script. You can cut and paste this section into the file /etc/datbkr.conf if you don't want to edit the script directly. (recommended) This file will be sourced by the script and override any defaults.
Make sure the hostname is set correctly, or else datbkr will assume you want to access a remote dat server and fail.
Testing
This part expects you already can acess your dat, and you have
a blank tape inserted.
First see if mt-st is working OK for you:
# /usr/local/bin/mt-st -f /dev/tape tell
At block 0.
Now try the datbkr wrapper:
# datbkr-mt tell, status, offline
At block 0.
[status info]
[tape ejects]
Insert the tape again. Now the moment of truth:
# datbkr-mt mkpart 10, status, setpart 1, status
This should create a 10MB partition, print status, go to partition 1, print status. The status reports show the current partition. Make sure the second status says partition=1.
If this does not work for you I don't know what to tell you. : P
Backing up
If all is working well let's try your first back-up:
# datbkr -e -s -d /tmp
Tape check: OK
All data will be erased on this tape!
Proceed? (y/N) y
Check for tape partitions: OK
Erase index partition: Done
Erase data partition: Done
Changing directory to: /tmp
Estimating size: 7.8M
Backing up: *
Written: 8701K, 8910336 bytes
Back up complete.
Change to index partition: Compress index: Write index to tape: Done
Ejecting tape: Done
All Operations Finished.
Wasn't that nice? Don't forget to look in your mail box for that nice backup report!
Restoring data
Reinsert the tape....let's make sure all the data got on there:
# cd /tmp; mkdir tmp1; cd tmp1
# datbkr-mt setpart 1
# tar xvf /dev/tape
tape.log
tape.dir.gz
Now let's dump the backup:
# datbkr-mt setpart 0
# tar xvf /dev/tape
[file listing]
If it does not dump or you get tape.log and tape.dir.gz again, the script had a problem changing the partitions on your tape. email me. Otherwise...that's it
Let's take a look at the top of your tape.dir:
rec 0: drwx------ root/root 0 1998-08-29 10:47 kfm-cache-0/
rec 1: prw------- root/root 0 1998-08-29 13:47 kfm_0_229_0.0
rec 2: prw------- root/root 0 1998-08-29 13:47 kio_0_229_0.0
rec 3: -rw------- root/root 5001065 1998-06-28 21:13 tape.dir
rec 9772: -rw------- root/root 1012 1998-08-28 21:15 tape.log
rec 9775: -rw------- root/root 559 1998-06-28 21:13 tape.status
rec 9778: drwxr-x--- root/root 0 1998-08-29 13:09 usr1/
....
Notice the record sizes are 512 byte (tar) blocks. These can be used to easily do QFA (quick file access) restores. You do this by:
# datbkr-mt seek [ RECORD / (TAPEBLKSIZE / 512) ]
By default datbkr uses a 512 byte tape block size. This is 1:1 with the tar records. IE to start extracting with 'tape.status':
# datbkr-mt seek 9775
# tar xvf /dev/tape
If you do alot of incremental restores, the above can be automated with some light scripting.