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Wed, 20 Apr 2022 01:51:34 -0400 (EDT) Date: Wed, 20 Apr 2022 07:51:32 +0200 From: Klaus Jensen To: Christoph Hellwig Subject: Re: [PATCH 4/5] hw/nvme: do not auto-generate uuid Message-ID: References: <20220419121039.1259477-1-its@irrelevant.dk> <20220419121039.1259477-5-its@irrelevant.dk> <20220420053336.GA2063@lst.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ithiIFUu6dgqq7Q/" Content-Disposition: inline In-Reply-To: <20220420053336.GA2063@lst.de> Received-SPF: pass client-ip=66.111.4.26; envelope-from=its@irrelevant.dk; helo=out2-smtp.messagingengine.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Keith Busch , Klaus Jensen , Luis Chamberlain , qemu-devel@nongnu.org, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --ithiIFUu6dgqq7Q/ Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Apr 20 07:33, Christoph Hellwig wrote: > On Tue, Apr 19, 2022 at 02:10:38PM +0200, Klaus Jensen wrote: > > From: Klaus Jensen > >=20 > > Do not default to generate an UUID for namespaces if it is not > > explicitly specified. > >=20 > > This is a technically a breaking change in behavior. However, since the > > UUID changes on every VM launch, it is not spec compliant and is of > > little use since the UUID cannot be used reliably anyway and the > > behavior prior to this patch must be considered buggy. >=20 > So unlike the EUI, UUIDs are designed to be autogenerated even if the > current algorithm is completely broken. We'd just need to persist them. > Note that NVMe at least in theory requires providing at least on of > the unique identifiers, and the UUID is the only one designed to be > autogenerated in a distributed fashion. I understand, but it boils down to the fact that we do not have a general method of storing "metadata" like this persistently. But maybe it is time that we come up with something to do this. --ithiIFUu6dgqq7Q/ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEUigzqnXi3OaiR2bATeGvMW1PDekFAmJfn2IACgkQTeGvMW1P Deni+AgAwNW+z1CNbaj/tw+wPHGCXfYYw8APQblegSVX8wd3TRH4NbhkBK8glIAy 6UOwVFUWVpLhOQ5fZtN+gD/HN2ZXeLhv8/m4eL75p22AMdhGn/lBtqKmEGupKhpF Fj7ZkP0BYAXGzVNMQo0tv+2LFCwMAAsNTxCZIhft5idWXXwt5U5g2nsw9FQ4SpFP VcPEu2QJ1nkJmCwfkIajmMhCCRLmCGCp1lwQ1ntcTEYK/5vASyeFbJYgUZRQwGN9 OW2zn2Txx1H1wfvjR4rTFxF7xditU5qTUFUP1/dnlK9smC10H3/8v8OKrTBLz3de Ht53CxK9rYcaxdsCJL5/tnB7P3SCJg== =AqOo -----END PGP SIGNATURE----- --ithiIFUu6dgqq7Q/--