My laptop is something I should *really* backup, since most of my files and stuff I’m working on is there. Since I’m too lazy to do this regularly though I setup an automated system to do this after I re-installed it this week.
My objective was to setup a backup system that would always run automatically, without me having to press any buttons. Incremental backups were a must. Keeping multiple days of backups was also a relatively high priority.
Dirvish is a perl wrapper for rsync. It’s main feature is to automate running incremental rsync backups on a regular basis without too much hassle. Having worked with it alot before it seemed the obvious choice for running my laptop backups.
Before I continue, some terminology:
Server: the machine running dirvish, in this case my desktop
Client: the machine with the files, in this case my laptop (littlebrick)
Bank: A directory where dirvish stores backups (eg. /backup)
Vault: A particular backup source (eg, my laptop)
Branch: A particular run of a vault (usually, daily)
DHCP
First, I needed to setup my laptop to have a static ip address on the wireless, which uses dhcp.
/etc/dhcpd.conf
...
host littlebrick {
hardware ethernet 00:1b:77:37:af:3d;
fixed-address 10.0.2.90;
}
...
DNS
and then I added this ip to the local dns server.
/var/named/master/db.internal
...
littlebrick A 10.0.2.90
...
Now I can specify the laptop by hostname in the config files later. You could skip this step and just use the ip or /etc/hosts of course.
SSH
Next step was to generate an ssh key, so the server could connect without a password
laptop# ssh-keygen
laptop# cat id_rsa.pub > /root/.ssh/authorized_keys2
laptop# scp id_rsa root@desktop:~/.ssh/
I set the laptop to allow root ssh (I’ll tidy this up a bit later), and then tested the desktop root user could ssh to the laptop.
Actually, the default in most cases is to allow ssh access as root (either via password or key). I think this is fairly nuts as a default, and usually change it pretty quickly
Dirvish
Once that’s done I started on dirvish. On the server I installed dirvish, and the client already had rsync, so nothing to install there. With that done I started configuring dirvish. All the config for this needs to be done on the server.
Fedora didn’t provide any default master.conf for dirvish, so I copied one I’d written before, and made a few small changes.
/etc/dirvish/master.conf
bank:
/home/backup
exclude:
lost+found/
/var/log/
/var/tmp/
/var/run/
/var/lock/
/mnt/
/media/
/sys
/dev/
/proc/
/tmp/
/vmlinuz*
/initrd*
.gvfs
Runall:
littlebrick 00:00
# by default we keep backups for 7 days
expire-default: +7 days
expire-rule:
# MIN HR DOM MON DOW STRFTIME_FMT
* * * * 1 +1 months
* * 1 * * +1 year
#
# permissions for logs, etc.
meta-perm: 600
Most of this is fairly self explanatory – the bank is the directory where all the backups will be kept. The exclude rules specify directories that we don’t want to include in the backups.
The expire rules are setup to keep the first backup of the month for a year, and the first of the week for a month, and all other backups for 7 days. I’ve found this to work well in the past. Obviously, it’s flawed here, but I’ll get to that later.
server# mkdir -p /home/backup/littlebrick/dirvish
Then, setup the default.conf in this directory. (the format here is $bank/$vault/dirvish)
/home/backup/littlebrick/dirvish.conf
client: littlebrick
tree: /
xdev: 0
index: none
image-default: %Y%m%d
image-perm: 700
Most of the options used here are fairly obvious, I want to backup the root of the host littlebrick, without keeping any indexes, and with a permission of 700 on the backup directory, which should be named in a YYYYMMDD format (you can add times and stuff here, but i’ve never felt the need. Keeping it in this simple format makes it easier to script stuff).
The xdev option specifies whether rsync should move from the original file system. Since /home is seperate from /, and has most of my stuff xdev needs to be turned off here. A value of 0 here is false (don’t stick to one file system), all other values (including the word false) will be interpreted as true.
With that done it’s time to test it. Hopefully it’ll “just work” ™.
server# dirvish --vault littlebrick --init
Knowing this would take ages, I went to make some coffee. Before it finishes run get the exact rsync command ran on the client from ps.
With that command edit /root/.ssh/authorized_keys2 (on the client) to look like this:
command="rsync --server --sender -vlHogDtpre.iLs --numeric-ids . /",from="10.0.2.5",no-port-forwarding,no-X11-forwarding,no-agent-forwarding ssh-rsa UrCysuKiGZRQzAfypvZNUuOmcPHu
lZy/B31Mje8UfooJCurM3JKL0t7U7mbor2Fs43OVZhUp6m1xburbDpFOtzKU0UDMO0MopRZ6q8si6fUP5oqAQAE2
U3Pieq3qJGLYzUB3zzzoDromtsYXbCwWDJsVdVVo6yvKNiSDWBZAo2UeyqRtsPuavVhuHqOxwu2/Fqu
aXq+vBkguC8ausv+wnSXhR9TINA7jDlu6g4pkkl7eCvOelzxvJ6O62kimt6JNWHJTHUMwue/mwSog8HPmACwY/OSOtelAih76v0Pur6dlMZT5cw1oOnU8DBXjt1e3V2Mw5wQxMxorBtXHeYxw== root@littlebrick
Where the command is the rsync command is the one from ps earlier, and the ip address is the ip of the dirvish server. With that done, edit sshd_config and set: “PermitRootLogin forced-commands-only”
Then I just added a script to /etc/cron.daily on the server to run it daily
/etc/cron.daily/00dirvish
dirvish-runall
dirvish-expire
dirvish-runall will backup any vaults specified in the runall section of /etc/dirvish/master.conf. dirvish-expire deletes any images that have been lying around longer than the expire time.
Still to do….
I find the pattern of keeping the first monthly backup for a year, and the first weekly for a month works well on systems where I expect backups to run every day, but obviously this won’t run daily. I’d like a system whereby I can ensure that the first successful backup can be kept for the month, regardless of what date it is. Dirvish doesn’t support anything this fancy, so it’ll take some scripting.
At the moment backups are set to run about 4am, this means they should generally be finished before I want to leave in the morning, but it’s not that unusual for me to be still working on my laptop at 4am. I’d like a script to stall/cancel backups if I’m still working. I’m thinking I could do this by querying the state of gnome-screensaver…
