subvol copying

subvol copying

[Russell Coker]

A user of a workstation has a home directory /home/john as a subvolume.  I 
wrote a cron job to make read-only snapshots of it under /home/john/backup 
which was fortunate as they just ran a script that did something like
"rm -rf ~".

Apart from copying dozens of gigs of data back, is there a good way of 
recovering it all?  Whatever you suggest isn't going to work for this time 
(the copy is almost done) but will be useful for next time.

I'm guessing that I can't delete a subvol that has other subvols under it.

Should I have put the backups under /backup instead so that I could just 
delete the corrupted subvol and make a read-write snapshot of the last good 
one?

-- 
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My Documents Blog    http://doc.coker.com.au/

Re: subvol copying

[Gabriel de Perthuis]

> A user of a workstation has a home directory /home/john as a subvolume.  I 
> wrote a cron job to make read-only snapshots of it under /home/john/backup 
> which was fortunate as they just ran a script that did something like
> "rm -rf ~".
> 
> Apart from copying dozens of gigs of data back, is there a good way of 
> recovering it all?  Whatever you suggest isn't going to work for this time 
> (the copy is almost done) but will be useful for next time.
> 
> Should I have put the backups under /backup instead so that I could just 
> delete the corrupted subvol and make a read-write snapshot of the last good 
> one?

You can move subvolumes at any time, as if they were regular directories.

For example: move the backups to an external location, move what's left
of the home to another location out of the way, and make a snapshot to
restore.

Re: subvol copying

[Chris Murphy]

On May 15, 2013, at 1:40 AM, Gabriel de Perthuis <g2p.code@gmail.com> wrote:

> 
> You can move subvolumes at any time, as if they were regular directories.

In the example case, the subvolumes are read-only. So is it possible to make a read-only subvolume (snapshot) read-writable? And is it possible to make a read-writeable snapshot of a read-only subvolume?


Chris Murphy

Re: subvol copying

[Harald Glatt]

On Wed, May 15, 2013 at 6:43 PM, Chris Murphy <lists@colorremedies.com> wrote:
>
> On May 15, 2013, at 1:40 AM, Gabriel de Perthuis <g2p.code@gmail.com> wrote:
>
>>
>> You can move subvolumes at any time, as if they were regular directories.
>
> In the example case, the subvolumes are read-only. So is it possible to make a read-only subvolume (snapshot) read-writable? And is it possible to make a read-writeable snapshot of a read-only subvolume?
>
>
> Chris Murphy
>
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You make a ro snapshot rw by creating a snapshot of it that is rw. So
yes to both questions, by doing the same thing in both cases.

Re: subvol copying

[Chris Murphy]

On May 15, 2013, at 10:44 AM, Harald Glatt <mail@hachre.de> wrote:

> 
> You make a ro snapshot rw by creating a snapshot of it that is rw. So
> yes to both questions, by doing the same thing in both cases.

In other words, a normal snapshot (without -r) of a read-only snapshot will create a rw snapshot?

In any case, for the OP, making a rw snapshot of the last backup ro snapshot, and putting it in place of the home folder is the way to do the rollback.


Chris Murphy

Re: subvol copying

[Harald Glatt]

On Wed, May 15, 2013 at 7:28 PM, Chris Murphy <lists@colorremedies.com> wrote:
>
> On May 15, 2013, at 10:44 AM, Harald Glatt <mail@hachre.de> wrote:
>
>>
>> You make a ro snapshot rw by creating a snapshot of it that is rw. So
>> yes to both questions, by doing the same thing in both cases.
>
> In other words, a normal snapshot (without -r) of a read-only snapshot will create a rw snapshot?

Yes