delete recursivly subvolumes?

delete recursivly subvolumes?

[Ulli Horlacher]

I am a master in writing unnecessary software :-}
"I have a great idea! I'll write a program for this!"
(some time and many lines of code later)
"ARGH... there is already such a program and it is better than mine!"

This time I ask BEFORE I do the coding:

Is there a command/script/whatever to remove subvolume which contains
(somewhere) other subvolumes?

Example:

root@xerus:/test# btrfs_subvolume_list /test/ | grep /tmp
/test/tmp
/test/tmp/xx/ss1
/test/tmp/xx/ss2
/test/tmp/xx/ss3

root@xerus:/test# btrfs subvolume delete /test/tmp
Delete subvolume (no-commit): '/test/tmp'
ERROR: cannot delete '/test/tmp': Directory not empty



-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK         
Universitaet Stuttgart         E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<20190705193945.GB23600@tik.uni-stuttgart.de>

Re: delete recursivly subvolumes?

[Ulli Horlacher]

On Fri 2019-07-05 (21:39), Ulli Horlacher wrote:

> Is there a command/script/whatever to remove subvolume which contains
> (somewhere) other subvolumes?

ADONN QUESTION! :-)

Is there a command/script/whatever to snapshot (copy) a subvolume which
contains (somewhere) other subvolumes?

Example:

root@xerus:/test# btrfs_subvolume_list /test/ | grep /tmp
/test/tmp
/test/tmp/xx/ss1
/test/tmp/xx/ss2
/test/tmp/xx/ss3

I want to have (with one command):

/test/tmp --> /test/tmp2
/test/tmp/xx/ss1 --> /test/tmp2/xx/ss1
/test/tmp/xx/ss2 --> /test/tmp2/xx/ss2
/test/tmp/xx/ss3 --> /test/tmp2/xx/ss3

-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK         
Universitaet Stuttgart         E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<20190705193945.GB23600@tik.uni-stuttgart.de>

Re: delete recursivly subvolumes?

[Hugo Mills]

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On Fri, Jul 05, 2019 at 09:47:20PM +0200, Ulli Horlacher wrote:
> On Fri 2019-07-05 (21:39), Ulli Horlacher wrote:
> 
> > Is there a command/script/whatever to remove subvolume which contains
> > (somewhere) other subvolumes?
> 
> ADONN QUESTION! :-)
> 
> Is there a command/script/whatever to snapshot (copy) a subvolume which
> contains (somewhere) other subvolumes?
> 
> Example:
> 
> root@xerus:/test# btrfs_subvolume_list /test/ | grep /tmp
> /test/tmp
> /test/tmp/xx/ss1
> /test/tmp/xx/ss2
> /test/tmp/xx/ss3
> 
> I want to have (with one command):
> 
> /test/tmp --> /test/tmp2
> /test/tmp/xx/ss1 --> /test/tmp2/xx/ss1
> /test/tmp/xx/ss2 --> /test/tmp2/xx/ss2
> /test/tmp/xx/ss3 --> /test/tmp2/xx/ss3

   Remember that this isn't quite so useful, because you can't make
read-only snapshots in that structure.

   Generally, I'd recommend not having nested subvols at all, but to
put every subvol independently, and mount them into the places you
want them to be. That avoids a lot of the issues of nested subvols,
such as the ones you're trying to deal with here.

   Hugo.

-- 
Hugo Mills             | "You know, the British have always been nice to mad
hugo@... carfax.org.uk | people."
http://carfax.org.uk/  |
PGP: E2AB1DE4          |                         Laura Jesson, Brief Encounter

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Re: delete recursivly subvolumes?

[Ulli Horlacher]

On Fri 2019-07-05 (19:51), Hugo Mills wrote:

> > Is there a command/script/whatever to snapshot (copy) a subvolume which
> > contains (somewhere) other subvolumes?
> > 
> > Example:
> > 
> > root@xerus:/test# btrfs_subvolume_list /test/ | grep /tmp
> > /test/tmp
> > /test/tmp/xx/ss1
> > /test/tmp/xx/ss2
> > /test/tmp/xx/ss3
> > 
> > I want to have (with one command):
> > 
> > /test/tmp --> /test/tmp2
> > /test/tmp/xx/ss1 --> /test/tmp2/xx/ss1
> > /test/tmp/xx/ss2 --> /test/tmp2/xx/ss2
> > /test/tmp/xx/ss3 --> /test/tmp2/xx/ss3
> 
>    Remember that this isn't quite so useful, because you can't make
> read-only snapshots in that structure.

ss1 ss2 and ss3 are indeed read-only snapshots!
Of course they do not contain other subvolumes.


>    Generally, I'd recommend not having nested subvols at all, but to
> put every subvol independently, and mount them into the places you
> want them to be. That avoids a lot of the issues of nested subvols,
> such as the ones you're trying to deal with here.

*I* do it this way from the very beginning :-)
But I have *users* with *strange* ideas :-}

I need to handle their data.


-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK         
Universitaet Stuttgart         E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<20190705195142.GQ32479@carfax.org.uk>

Re: delete recursivly subvolumes?

[Hugo Mills]

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On Fri, Jul 05, 2019 at 09:56:39PM +0200, Ulli Horlacher wrote:
> On Fri 2019-07-05 (19:51), Hugo Mills wrote:
> 
> > > Is there a command/script/whatever to snapshot (copy) a subvolume which
> > > contains (somewhere) other subvolumes?
> > > 
> > > Example:
> > > 
> > > root@xerus:/test# btrfs_subvolume_list /test/ | grep /tmp
> > > /test/tmp
> > > /test/tmp/xx/ss1
> > > /test/tmp/xx/ss2
> > > /test/tmp/xx/ss3
> > > 
> > > I want to have (with one command):
> > > 
> > > /test/tmp --> /test/tmp2
> > > /test/tmp/xx/ss1 --> /test/tmp2/xx/ss1
> > > /test/tmp/xx/ss2 --> /test/tmp2/xx/ss2
> > > /test/tmp/xx/ss3 --> /test/tmp2/xx/ss3
> > 
> >    Remember that this isn't quite so useful, because you can't make
> > read-only snapshots in that structure.
> 
> ss1 ss2 and ss3 are indeed read-only snapshots!
> Of course they do not contain other subvolumes.

   What I'm saying is that you can't make a RO snapshot of test/tmp to
test/tmp2 and have your RO snapshots of ss1-3 in place within it.

   (OK, you could make the snapshot RW initially, snapshot the others
into place and then force it RO, but then you've just broken
send/receive on tmp2).

> >    Generally, I'd recommend not having nested subvols at all, but to
> > put every subvol independently, and mount them into the places you
> > want them to be. That avoids a lot of the issues of nested subvols,
> > such as the ones you're trying to deal with here.
> 
> *I* do it this way from the very beginning :-)
> But I have *users* with *strange* ideas :-}
> 
> I need to handle their data.

   That makes it more awkward. :(

   Hugo.

-- 
Hugo Mills             | "You know, the British have always been nice to mad
hugo@... carfax.org.uk | people."
http://carfax.org.uk/  |
PGP: E2AB1DE4          |                         Laura Jesson, Brief Encounter

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