From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from frost.carfax.org.uk ([85.119.82.111]:36240 "EHLO frost.carfax.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757293AbdIILAa (ORCPT ); Sat, 9 Sep 2017 07:00:30 -0400 Received: from hrm by frost.carfax.org.uk with local (Exim 4.80) (envelope-from ) id 1dqdUz-0007O8-Q5 for linux-btrfs@vger.kernel.org; Sat, 09 Sep 2017 11:00:29 +0000 Date: Sat, 9 Sep 2017 11:00:29 +0000 From: Hugo Mills To: linux-btrfs@vger.kernel.org Subject: Re: generic name for volume and subvolume root? Message-ID: <20170909110029.GF23980@carfax.org.uk> References: <20170909083551.GC22060@rus.uni-stuttgart.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="3yNHWXBV/QO9xKNm" In-Reply-To: <20170909083551.GC22060@rus.uni-stuttgart.de> Sender: linux-btrfs-owner@vger.kernel.org List-ID: --3yNHWXBV/QO9xKNm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sat, Sep 09, 2017 at 10:35:51AM +0200, Ulli Horlacher wrote: > As I am writing some documentation abount creating snapshots: > Is there a generic name for both volume and subvolume root? > > Example: > > root@fex:~# btrfs subvol show /mnt > ERROR: not a subvolume: /mnt > > root@fex:~# btrfs subvol show /mnt/test > /mnt/test is toplevel subvolume > > root@fex:~# btrfs subvol show /mnt/test/data > /mnt/test/data > Name: data > UUID: b32a5949-dfd6-ef45-8616-34ae4cdf6fb8 > (...) > > root@fex:~# btrfs subvol show /mnt/test/data/sw > ERROR: not a subvolume: /mnt/test/data/sw > > > I can create snapshots of /mnt/test and /mnt/test/data, but not of /mnt > and /mnt/test/data/sw > > Is there a simple name for directories I can snapshot? Subvolume. If you can snapshot it, it's a subvolume. Some subvolumes are also snapshots. (And all snapshots are subvolumes). The subvolume with ID 5 (or ID 0, which is an alias) is the "top level subvolume", and has the unique property that it can't be renamed, deleted or replaced, where all other subvolumes can be. Hugo. -- Hugo Mills | Well, you don't get to be a kernel hacker simply by hugo@... carfax.org.uk | looking good in Speedos. http://carfax.org.uk/ | PGP: E2AB1DE4 | Rusty Russell --3yNHWXBV/QO9xKNm Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJZs8nNAAoJEFheFHXiqx3kYMAP/2epPkkbbCc89PZXZHKM//iJ 8MlEVvOGaX7nh1V3Ag4K+JQWBdG3yMjq4Y7shsRFI3Soz9EuIS35z3LZwfg0uPIu SySO0jjUjiYTR5P0B3esNkMbH01L08+BGcAUF1ffxMu1+ATxhe8SXUCx2BSgYd2S c6XEVNObd1TNrf26LbckyXgf8cCMJQMC0INM/x8joVHvDzt4i65DDpbojVBk0Je5 9Ux09hMChrea1KvYwPWG0zyUpPFIgUMa2gh7po1cZd2VIx1kYZuYvk4/Q7elFOLo t7rZrvfaQ6r8JiG5eVu4SiikX38twZ4JS/UxeGz6p32L3vpk7ppLWen6t3pKIZDp 6kFesxNch+b/q1sIVsPSFj9xpfUqmyRZFYERmW+rTgIcZZvRl44mV81qONZ9rcEB 7czu1lKY+4RwgFVzK1BfG8KKS4LgPRbP54dp9c1n6wAYRoAlL6iXgno4p4gfk7hP SzxTimskorkcu1rSd9ggyULfiDdMpkWNzH8sjl3AIM0Q0QV/VNmnIgam6VBOtMYD eMYM9ua7uhI+DlBptbu7ONRVCtXUH3D45Q2bj/6Wa3bhZXRT2NfvNNjdoUdufF+w WbWfVzGDxjjaw0R933IyKfGHligjH4Q8AhKqHQZRyz1rkxB8e3s4Z++xD41zDmco oqQPW4M9RIZP0nDdagEc =e10i -----END PGP SIGNATURE----- --3yNHWXBV/QO9xKNm--