From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Superblock backup Date: Fri, 11 May 2012 08:50:57 +1000 Message-ID: <20120511085057.27790c1a@notabene.brown> References: <20120510174431.GA3019@lazy.lzy> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/kLWb2EMdFnvEJmFDzSLPJf="; protocol="application/pgp-signature" Return-path: In-Reply-To: <20120510174431.GA3019@lazy.lzy> Sender: linux-raid-owner@vger.kernel.org To: Piergiorgio Sartor Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/kLWb2EMdFnvEJmFDzSLPJf= Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 10 May 2012 19:44:31 +0200 Piergiorgio Sartor wrote: > Hi, >=20 > again, following the RAID-5 story, I was wondering > if could make sense to have a new superblock type, > let's say 2.x, having backup copies (of persistent > or quasi persistent data) in different areas of the > drive components. > This would be similar to filesystem or gpt. >=20 > Is there anything planned for this? This is one of the idea that has floated around in my head for a while, possibly a v1.3 metadata. However my thought there was always to protect against a bad block on the device. Protecting against data corruption due to bugs or sys-admin mistak= es is always best handled by backups. e.g. take a 'dump' (either binary or textual) of the metadata every day, or every reboot or something. (And store it on a different host). Both are probably useful, but for the recently problem, a regular backup would be the most useful. >=20 > In any case, it would be still interesting to have > a "backup" capability at hand, like a "dd" of the > superblock to some secure file. "mdadm -E" would probably be enough - just write a cron job :-) NeilBrown >=20 > Any idea or suggestions? >=20 > Thanks, >=20 > bye, >=20 --Sig_/kLWb2EMdFnvEJmFDzSLPJf= Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBT6xGUTnsnt1WYoG5AQIScA//dTbkAugvU+KFlvUIZXNI+JqyOlV5n/Q9 AyXx7TWU8vOcB5V+jTV828/iun8KXfWTeMYU7Px5QNmAhIpobQqRh47JdwJDajxr XXDMScIcI6OFTB1oUa9ycqV7P2mXNyIzAO3966oTTs/08qVQIYrpBAzjM5vX7M0O U85O30iR1k34dk63OXak7rIPpc/HJevOD4bwEiIQxYi5R5hrVDR3AsdgevuZ2coj 9sChIoiHlJ9gSC81FYizqI4hc1nP8BGOofyyzBhvNSFTzQCIeKQEFXXCf5rL8O0T jcKie+7JS/N28ZlFXH+Hrb5RW9gNGOfA4qKc6NfIoC7yvB9Fa3BHeTaPvnJZ3pIc jp5hNDDv5XT+XHQno3VqH0s//Y6PLPieoVtd841+dGBoryU1VGwoKuM0CHMiGNcB M18a0Ls7wLtX6rgSUlsKz93ptQW+mO7xQDkBaJWWK85VGucxW9NftopOByuJwKlH 447uaqVt3FMO0yUxYFn647JTy1hdN+StsvgHRbhCCWWWz0J5ptz9ZfT9j9iiiPfE gR70N5qXSK168BgAmFtJxqjeen02OadnWm791BFQFNhXiEJGCKCh44eZox3r/Y77 E/4UDidShPUh7vVJltHoNTQMNKcHppPOxTLR2PzghPC8bR7rEzceKLVtQbL5hNrd cbIFF/SZsy8= =9LDd -----END PGP SIGNATURE----- --Sig_/kLWb2EMdFnvEJmFDzSLPJf=--