Date: Wed, 7 Sep 2011 11:45:56 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Andriy Gapon <avg@FreeBSD.org> Cc: freebsd-fs@FreeBSD.org, Artem Belevich <art@FreeBSD.org>, Martin =?utf-8?Q?Matu=C5=A1ka?= <mm@FreeBSD.org> Subject: Re: "can't load 'kernel'" on ZFS root Message-ID: <20110907094554.GB1674@garage.freebsd.pl> In-Reply-To: <4E673751.5080503@FreeBSD.org> References: <20110907044800.GA96277@server.vk2pj.dyndns.org> <CAFqOu6jv93WKBLMDKPQCOKfOF6Q4zq6PWKQBjSgfWyVvkM4jFw@mail.gmail.com> <4E673751.5080503@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--qlTNgmc+xy1dBmNv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 07, 2011 at 12:20:17PM +0300, Andriy Gapon wrote: > on 07/09/2011 10:35 Artem Belevich said the following: > > It makes me wonder, though -- if we're probing devices anyways, why is > > zpool.cache existence mandatory? According to the name it's a *cache*, > > presumably to speed up zpool detection on a normal boot. Perhaps we > > can fall back to probing all drives if zpool.cache is missing. Slower > > boot definitely beats no booting at all. >=20 > Very good point indeed. >=20 > Pawel, Martin, do you know how the relevant code works? I suspect that y= ou do > :-) Maybe this could be improved trivially?... The zpool.cache file contains pools that are automatically imported at system start-up. There might be pools visible in the system that are not suppose to be automatically imported (eg. a pool on iSCSI disks on secondary cluster node - importing such pool automatically will corrupt the data). This is also not entirely true that we probe all the devices. We probe them at boot, yes, because we don't even know where to look for zpool.cache file, but once kernel is loaded we use info from zpool.cache to open GEOM providers. We fall back to probing all GEOM providers if something has changed in disk configuration and we can't find all the vdevs (eg. disk name changed). --=20 Pawel Jakub Dawidek http://www.wheelsystems.com FreeBSD committer http://www.FreeBSD.org Am I Evil? Yes, I Am! http://yomoli.com --qlTNgmc+xy1dBmNv Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAk5nPVIACgkQForvXbEpPzS1+QCdGQkXLrr/c7citG0829SIEoMs TaIAoJD9z+QrEULBolLDUUf3TzwzzsUU =kdL9 -----END PGP SIGNATURE----- --qlTNgmc+xy1dBmNv--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110907094554.GB1674>