[gentoo-user] Performing a backup during the boot sequence

[Allan Gottlieb <gottlieb@nyu.edu>]

For quite a while I have used the following steps to perform a
"single-user backup"

1.  Boot to single user mode via the grub command
        kernel /boot/vmlinuz root=/dev/sda6 single

2.  Type in the root password.

3.  Execute a single command
       /usr/local/sbin/ajg-backup-init-3
    which does the backup and then executes
       init 3

4.  This gets me to multi-user mode.

I would like to automate this so that booting directly to multi-user
mode via
        kernel /boot/vmlinuz root=/dev/sda6

All I need to do is to execute the single command
       /usr/local/sbin/ajg-backup-init-3
at the right moment.
This didn't seem hard; I want it after everything in boot but before
everything currently in default.  So I was going to put it in
default with a "before *" in depend()

Reading the gentoo handbook chapter B4.d "Writing Init Scripts"
I find two comments criticizing this approach

1.  "You can also use the "*" glob [argument to before] to catch all
    services in the same runlevel, although this isn't advisable".

2.  "Note: Make sure that --exec actually calls a service and not just a
    shell script that launches services and exits -- that's what the
    init script is supposed to do."

I can see problems with multiple "before *" directives, but no other
script has one so I think I would be OK with my "before *".

Criticism 2 has me concerned since my backup routing is indeed a shell
script that exits.  Indeed, my backup is not really a service so I am
worried that I shouldn't be using an initscript at all.

Any advice/comments would be welcome.

thanks,
allan