Am 2014-11-29 um 23:18 schrieb Marc MERLIN:
On Sat, Nov 29, 2014 at 10:51:08PM +0100, Jakob Schürz wrote:
Am 2014-11-29 um 22:11 schrieb Marc MERLIN:
On Sat, Nov 29, 2014 at 09:34:01PM +0100, Jakob Schürz wrote:
Hi there!
I made a script to do backup with btrfs on a external HD.
You can see the function, how it works, and how it's to be used on
my site http://linux.xundeenergie.at/doku.php?id=mkbtrbackup
The site is in german. An english one will follow later.
Do you want some explanations?
Sure, how is it different from those 3?
https://btrfs.wiki.kernel.org/index.php/Incremental_Backup#Available_Backup_Tools
Wheter i haven't seen it, or this scripts can't do recursive backup...
That's probably right, at least not automatically.
And that's why i made the script. :)
If you have subvolumes in subvolumes (for example: /home,
/home/user1, /home/user2 /var, /var/spool, /var/lib are extra
subvolumes IN the normal filetree from linux), my script takes them
all.
For me, they are all subvolumes also mounted on /mnt/btrfs_poolx
so I backup from there.
That's also possible with my skript, because you can control it with an
config-file.
For example you have
/
|-@
|-@home
`-@var
And you want all your snapshots of this 3 subvolumes in separate
directories with timestamp (and maybe .hourly_X-Tag)
put in the config:
SNPMNT=/path/to/btrfs-poolmount
BKPMNT=/path/to/external/HD/mountpoint
backup @ roots backup/roots
backup @home homes backup/homes
backup @var vars backup/vars
start the skript with
mkbtrbackup create --interval hourly -c /path/to/backupconfig
you get in /path/to/btrfs-poolmount 3 directories (roots, homes and
vars), and on /path/to/external/HD/mountpoint one directoriy "backup",
including also the three given subdirectories from the 4th coloumn
(leave this coloumn blank, no auto-transfer to the external HD!!!)
in this subdirectories you get subvolumes like
@.20141130-115001.hourly_0
@home.20141130-115001.hourly_0
@var.20141130-115001.hourly_0
AND they are rotated automatically.
And my script changes the fstab-entry in the new snapshot.
The original has the option "subvol=@SUBVOL", where @SUBVOL is the
name of the original system.
I don't need to do that, my script updates a symlink pointing to the
last snapshot, and you can use subvol=symlink-name
I'm trying on this, it's not finished. There are many discussions about.
What is better... modify grub.cfg on each snapshot, work with symlinks...
I create one symlink @*.CURRENT. I will rename it to .LAST... so i can
do the same with a static grub-entry
You get a systemd-unit, in the tarball, which makes a snapshot from
your system, on successful boot, so you can switch back fast, if an
update destroyed your system.
And it is for minimal-systems... no python, no perl, no java... only
shell(bash) :-)
That makes sense, thanks for explaining.
For example... on an raspberry Pi it would be a good thing. :)
Hope, you try it, and give me some feedback. ;-)
Jakob
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