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At Wed, 26 May 2010 17:17:45 +0200 Daniel Troeder <daniel@×××××××××.com> wrote: |
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> On 05/26/2010 12:30 AM, Allan Gottlieb wrote: |
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>> For quite a while I have used the following steps to perform a |
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>> "single-user backup" |
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>> |
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>> 1. Boot to single user mode via the grub command |
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>> kernel /boot/vmlinuz root=/dev/sda6 single |
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>> |
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>> 2. Type in the root password. |
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>> |
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>> 3. Execute a single command |
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>> /usr/local/sbin/ajg-backup-init-3 |
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>> which does the backup and then executes |
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>> init 3 |
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>> |
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>> 4. This gets me to multi-user mode. |
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>> |
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>> I would like to automate this so that booting directly to multi-user |
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>> mode via |
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>> kernel /boot/vmlinuz root=/dev/sda6 |
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>> |
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>> All I need to do is to execute the single command |
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>> /usr/local/sbin/ajg-backup-init-3 |
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>> at the right moment. |
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>> This didn't seem hard; I want it after everything in boot but before |
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>> everything currently in default. So I was going to put it in |
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>> default with a "before *" in depend() |
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>> |
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>> Reading the gentoo handbook chapter B4.d "Writing Init Scripts" |
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>> I find two comments criticizing this approach |
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>> |
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>> 1. "You can also use the "*" glob [argument to before] to catch all |
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>> services in the same runlevel, although this isn't advisable". |
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>> |
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>> 2. "Note: Make sure that --exec actually calls a service and not just a |
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>> shell script that launches services and exits -- that's what the |
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>> init script is supposed to do." |
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>> |
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>> I can see problems with multiple "before *" directives, but no other |
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>> script has one so I think I would be OK with my "before *". |
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>> |
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>> Criticism 2 has me concerned since my backup routing is indeed a shell |
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>> script that exits. Indeed, my backup is not really a service so I am |
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>> worried that I shouldn't be using an initscript at all. |
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>> |
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>> Any advice/comments would be welcome. |
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>> |
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> You could create a LVM-snapshot of the partition/data you wish to backup |
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> at "before *" or inside "boot" and then later run the backup on the |
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> mounted snapshot, removing it afterwards. |
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Thanks, but I am not trying to minimize the boot time. The disk to disk |
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dumps are fast enough (I do the slower copy to a remote site after |
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logged in). I am just trying to have the dump done at the right point |
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in the boot sequence without manually going into single user mode. If I |
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could automate the snapshot, I could automate the dump. |
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Indeed rereading the gentoo manual, I see that the requirement that you |
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invoke a service and not a script that exits, applies only to |
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start-stop-daemon, so I will just try to invoke my script directly from |
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the init script. |
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|
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allan |
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