From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH v2 03/12] raid5-cache: add a new policy Date: Fri, 09 Dec 2016 08:22:10 +1100 Message-ID: <87vauu15h9.fsf@notabene.neil.brown.name> References: <20161205153113.7268-1-artur.paszkiewicz@intel.com> <20161205153113.7268-4-artur.paszkiewicz@intel.com> <87d1h44lcj.fsf@notabene.neil.brown.name> <87lgvr2uhk.fsf@notabene.neil.brown.name> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Artur Paszkiewicz , shli@kernel.org Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Thu, Dec 08 2016, Artur Paszkiewicz wrote: >>=20 >> How about we call it "resync_policy" which describes how to cope with >> unexpected shutdown. Options include: >>=20 >> full regenerate all redundancy info after a crash >> bitmap only regenerate redundancy info indicated by bitmap >> (both these suseptible to write-hole on raid456) >> journal raid456 only, though could theoretically be extended >> to raid1, raid10 : log transactions and replay after crash >> ppl raid456 only: log partial-parity before writes. >>=20 >> With external metadata, this must be set explicitly. With internal >> metadata, it is set best on flags etc. >>=20 >> Thoughts? I'm not really happy with "full", but I cannot think of a >> better name. > > I'm OK with this approach. A corresponding option will also be needed in > mdadm. But won't this name be a little misleading because this option is > not just about unexpected shutdown (where resync applies), but also > degraded array unexpected shutdown. So maybe something like > "consistency_policy" and "resync" option instead of "full"? "consistency_policy" and "resync" sounds good to me. Thanks. NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAlhJzwMACgkQOeye3VZi gbnxCA/9HQUEAhai9DaISQ1ZqvcsbpZbYNpd8tSnFLzX9vIJJAG0TdufEFL7aCfT jXIgNxJN/zUQlPD9TEb/ahPlvg8sWTlWlmTkSWK95S2YroA2sQFLnZj0Fs1qzcsI i+ULq2T7qETxsdmVyCxtOvB5VGaLpRl9XCEdBHSubBdyaC3iUhE3T1xuw0utm9An mAnw+iTd7xOvOigkGPUuEFFyG4iA2BEdw23R2YSk6IB8TBOr4yUw5DHK5/ZGqAAC 6Ww8KkR2aRPind1c413yBI7c8Q2Kd9bWNFPlgeSyjgvy1APViHtAmqpNwDfjV0B7 80lRtzbDdIRAxSTek0C0XNmxkfY9Yl/hCDDa9iRb2uuK6xZXPNR/jDWgaYkXK0/G u4pq41QIhHTSIEU33T4x8lBti1HOi2fBaoGucuuxTnckZ5+xNoN2QFHdPOIvskIk MrbiBztxSlS7fHb7bGmVVe0HBp4wdMwGIVxsftRASkSGT67QPqR9CexHTyuZTZw0 Aq4HEggeVYB527eukMmlg8ZU7ba/PNsMH9qpHYt/qiaTut4JB2fLinYK4yF+2c7a z2HRb4eL42CWq2lt6RO/Vrh/bROugtt7NQ3wZly4yvoTzKB5A6TdcWWJr4sMmEuk fGVtJ9VwLHFH7aHyAyDNe5uNWlGlzKetKP1S4R6Jq5HfOCkyEo4= =0j1t -----END PGP SIGNATURE----- --=-=-=--