public inbox for linux-btrfs@vger.kernel.org
 help / color / mirror / Atom feed
From: Ulli Horlacher <framstag@rus.uni-stuttgart.de>
To: linux-btrfs@vger.kernel.org
Subject: Re: how do I know a subvolume is a snapshot?
Date: Wed, 17 Jul 2019 10:05:57 +0200	[thread overview]
Message-ID: <20190717080557.GA3462@tik.uni-stuttgart.de> (raw)
In-Reply-To: <1858db2d-8683-0ba9-cc13-9e654a1fa810@allchangeplease.de>

On Wed 2019-07-17 (09:45), Bernhard Kühnel wrote:
> Am 17.07.2019 um 01:24 schrieb Ulli Horlacher:
> 
> > How do I know that /mnt/tmp/ss is a snapshot?
> > I cannot see a snapshot identifier.
> 
> From the btrfs-subvolume man page:
> 
> >       A snapshot is a subvolume like any other, with given initial content. By default, snapshots are created
> >       read-write. File modifications in a snapshot do not affect the files in the original subvolume.

I know this, but my question was not "What is a snapshot".


> I believe the usual practice is to create snapshots with the -r flag and
> follow some naming convention (e.g. place them in a common .snapshots
> folder named by date), but you're free to switch between read-only and
> read-write mode for a snapshot at any time using the btrfs property command.

This is true also for my users and co-admins.
Though, I want to know which subvolume is a snapshot of what subvolume.

Non-toplevel subvolume snapshots have a Parent UUID - why not all?!
Or at least some kind of flag "I am a snapshot".


-- 
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:<1858db2d-8683-0ba9-cc13-9e654a1fa810@allchangeplease.de>

  reply	other threads:[~2019-07-17  8:06 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-16 23:24 how do I know a subvolume is a snapshot? Ulli Horlacher
2019-07-17  7:45 ` Bernhard Kühnel
2019-07-17  8:05   ` Ulli Horlacher [this message]
2019-07-17 10:33   ` Remi Gauvin
2019-07-17  8:23 ` Hans van Kranenburg
2019-07-17  8:57   ` misono.tomohiro
2019-07-17  9:06     ` Ulli Horlacher
2019-07-17  9:24       ` misono.tomohiro
2019-07-17  8:24 ` Nikolay Borisov
2019-07-17  9:11   ` Ulli Horlacher
2019-07-17 10:11     ` Nikolay Borisov
2019-07-17 10:29       ` Andrei Borzenkov
2019-07-17 11:19         ` Nikolay Borisov
2019-07-17 17:39           ` Andrei Borzenkov
2019-07-17 18:16             ` Nikolay Borisov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190717080557.GA3462@tik.uni-stuttgart.de \
    --to=framstag@rus.uni-stuttgart.de \
    --cc=linux-btrfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox