From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:2000 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753772AbaENOnH (ORCPT ); Wed, 14 May 2014 10:43:07 -0400 Message-ID: <1400078533.15603.175.camel@rh> Subject: Re: [PATCH] mkfs.btrfs: allow UUID specification at mkfs time From: James Shubin To: Brendan Hide Cc: Wang Shilong , Eric Sandeen , linux-btrfs , jshubin@redhat.com Date: Wed, 14 May 2014 10:42:13 -0400 In-Reply-To: <537360B2.50107@swiftspirit.co.za> References: <5372C457.3000706@redhat.com> <53731BE3.5010604@cn.fujitsu.com> <537360B2.50107@swiftspirit.co.za> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-mUl07/b7dfnsutxY9eAg" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: --=-mUl07/b7dfnsutxY9eAg Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2014-05-14 at 14:25 +0200, Brendan Hide wrote: > On 14/05/14 09:31, Wang Shilong wrote: > > On 05/14/2014 09:18 AM, Eric Sandeen wrote: > >> Allow the specification of the filesystem UUID at mkfs time. > >> > >> (Implemented only for mkfs.btrfs, not btrfs-convert). > > Just out of curiosity, this option is used for what kind of use case? > > I notice Ext4 also has this option.:-) > Personally I can't think of any "average" or "normal" use case. The=20 > simplest case however is in using predictable/predetermined UUIDs. >=20 > Certain things, such as testing or perhaps even large-scale automation,= =20 > are likely simpler to implement with a predictable UUID. >=20 Exactly this! My use case is actually for storage automation. By using an internally generated UUID, it's one easy way to "track" which filesystem your automation code made. Example: https://github.com/purpleidea/puppet-gluster/blob/master/manifests/brick.pp= #L469 HTH, James --=-mUl07/b7dfnsutxY9eAg Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAABAgAGBQJTc4DFAAoJEF9gnLdaSQBg3SYP/1HnrhgkQUyW8bYbwBpjfAXP xFHhTy9nkU8qUxbWpBS/g7Cu4Ke4FWAr042Fu7Dh/x9BUEUuGGDCpo608EyTXb/r 8ZJJ7dT5ft4DVkar/BR6jfuT1o827E7siRRXTnjZfWQsdeRo6eRl4tsXAM4jYEgR /F/yaRT6xnhYX1q5q/dGT9qChkPALZKXpTb8iMgKXlVqobHGB9pGr9UOLavzdt5u rbS8M6GrvKYsIahvKSWpSliCAnjZPQjo1q3ACK3hiDiX/JoFHGXWUfDa2/iQP07w 7G9gBdyk8a+ZzJo8X2e4idV0YFvjoW4qPw6mp0xgzszFj3czQRFw7jU8t5BJgIqo qfPjFu09F2UaD4buuR1P9ivOot9NtZUoJg5R8fYImHOB0lqHQj0PkBr2sIS1x5db u2jqRsS1Ou/ws9OAlGfBsEBoII71X0RPEBN1KlhpgNVZ2PQOVwgXDvQE5X7OHhbH 2x1IGRgA6C0aqrXxZa/KUH3Asjl8LazDOv7UxPuslsxj3MixwqTTEypdNl/23Rvp DYGk8UIo0+QicpBFoV9PjdYBdPXqqssMUcwHWAzRIfmrNheFwvTnKqEquQMP/tqr CylBQhnNCI/DwQvECnEhO7wI84ToQyoT5Rg1KZACM4RkJqZFtkt/XiMr2XPjOi/o a2gkjo9OTF0ul60HysfA =wC/N -----END PGP SIGNATURE----- --=-mUl07/b7dfnsutxY9eAg--