Gentoo Archives: gentoo-user

From: Daniel Troeder <daniel@×××××××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Performing a backup during the boot sequence
Date: Wed, 26 May 2010 15:20:06
Message-Id: 4BFD3B99.20802@admin-box.com
In Reply to: [gentoo-user] Performing a backup during the boot sequence by Allan Gottlieb
1 On 05/26/2010 12:30 AM, Allan Gottlieb wrote:
2 > For quite a while I have used the following steps to perform a
3 > "single-user backup"
4 >
5 > 1. Boot to single user mode via the grub command
6 > kernel /boot/vmlinuz root=/dev/sda6 single
7 >
8 > 2. Type in the root password.
9 >
10 > 3. Execute a single command
11 > /usr/local/sbin/ajg-backup-init-3
12 > which does the backup and then executes
13 > init 3
14 >
15 > 4. This gets me to multi-user mode.
16 >
17 > I would like to automate this so that booting directly to multi-user
18 > mode via
19 > kernel /boot/vmlinuz root=/dev/sda6
20 >
21 > All I need to do is to execute the single command
22 > /usr/local/sbin/ajg-backup-init-3
23 > at the right moment.
24 > This didn't seem hard; I want it after everything in boot but before
25 > everything currently in default. So I was going to put it in
26 > default with a "before *" in depend()
27 >
28 > Reading the gentoo handbook chapter B4.d "Writing Init Scripts"
29 > I find two comments criticizing this approach
30 >
31 > 1. "You can also use the "*" glob [argument to before] to catch all
32 > services in the same runlevel, although this isn't advisable".
33 >
34 > 2. "Note: Make sure that --exec actually calls a service and not just a
35 > shell script that launches services and exits -- that's what the
36 > init script is supposed to do."
37 >
38 > I can see problems with multiple "before *" directives, but no other
39 > script has one so I think I would be OK with my "before *".
40 >
41 > Criticism 2 has me concerned since my backup routing is indeed a shell
42 > script that exits. Indeed, my backup is not really a service so I am
43 > worried that I shouldn't be using an initscript at all.
44 >
45 > Any advice/comments would be welcome.
46 >
47 > thanks,
48 > allan
49 >
50 >
51 You could create a LVM-snapshot of the partition/data you wish to backup
52 at "before *" or inside "boot" and then later run the backup on the
53 mounted snapshot, removing it afterwards.
54
55 Bye,
56 Daniel
57
58 --
59 PGP key @ http://pgpkeys.pca.dfn.de/pks/lookup?search=0xBB9D4887&op=get
60 # gpg --recv-keys --keyserver hkp://subkeys.pgp.net 0xBB9D4887

Attachments

File name MIME type
signature.asc application/pgp-signature

Replies

Subject Author
Re: [gentoo-user] Performing a backup during the boot sequence Allan Gottlieb <gottlieb@×××.edu>