At Wed, 26 May 2010 17:17:45 +0200 Daniel Troeder <dan...@admin-box.com> wrote:
> On 05/26/2010 12:30 AM, Allan Gottlieb wrote: >> 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. >> > You could create a LVM-snapshot of the partition/data you wish to backup > at "before *" or inside "boot" and then later run the backup on the > mounted snapshot, removing it afterwards. Thanks, but I am not trying to minimize the boot time. The disk to disk dumps are fast enough (I do the slower copy to a remote site after logged in). I am just trying to have the dump done at the right point in the boot sequence without manually going into single user mode. If I could automate the snapshot, I could automate the dump. Indeed rereading the gentoo manual, I see that the requirement that you invoke a service and not a script that exits, applies only to start-stop-daemon, so I will just try to invoke my script directly from the init script. allan
