From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [md PATCH 08/23] md: don't set md arrays to readonly on shutdown. Date: Thu, 19 Apr 2012 08:48:33 +1000 Message-ID: <20120419084833.39379a6f@notabene.brown> References: <20120314043555.7978.75486.stgit@notabene.brown> <20120314044040.7978.64156.stgit@notabene.brown> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/yLBZ7szx3Uykn8uZjTJ3m5P"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Alexander Lyakas Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/yLBZ7szx3Uykn8uZjTJ3m5P Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Wed, 18 Apr 2012 18:37:56 +0300 Alexander Lyakas wrote: > Hi Neil, >=20 > > This could result in the shutdown happening when array is marked > > dirty, thus forcing a resync on reboot. =A0However if you reboot > > without performing a "sync" first, you get to keep both halves. > Can you pls clarify the last statement? "If you break it, you get to keep both halves" is a colloquial phrase meani= ng that that the person saying it takes no responsibility for any damage that the person being spoken to causes. When applied to software issues it is ironic (because when a thing 'breaks'= it doesn't result in two pieces like, for example, when a plate breaks) and so funny (I hope). (when applied to a RAID mirror, it is doubly ironic :-) If you force a fast shutdown without allowing a sync to happen=20 (e.g. reboot -f -n) there could be data on the way out to the array when the system actually reboots, so the array will be dirty, so a resync will be required when the system restarts. This might be undesirable, but that isn't my problem and is not the problem of md/raid. Rather the cause of the problem is the "reboot -f -n". i.e. "your" problem. "You" broke it, you get to keep both halves. Does that help? NeilBrown --Sig_/yLBZ7szx3Uykn8uZjTJ3m5P Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBT49EwTnsnt1WYoG5AQI9Kw//dTfv8RzaamK3tKqwxEnffB33bviIzkqv rCPlUsHIhdoonGQlKjVOhFnf10ZDgbwOFtWNGzg1zE0gSERmEYbF5cDWJoE3Ugij 3TPulnu8ZgzIlmo+O8o8yQwNJLAmrSo9aREvp6lWYCV2BHtCj3Hp2gBm0OuaQ2te i7DQ6jwWR8OHPEG5Ss1wDuFln1Qd061pFqNRObYmhw5+etUEposcd9KTsDb8i3Oo uDozaIb8UTGyILzVq8OdNq0937JuZpYUZI/gtzcKhDPjCnAKw+iayTAACagRtqFQ rHokLSkNak5op2O87uTluLGv6sxL7sQwNjdYBJzQjqXUyegodTN58kzMTbQd8iSX hzp3cG9jXz0CA3NcNFKi1P5FmQ8JLZ62fhobTADJB/ppvEudTUr96XXD0tSEje2e FMeGDf9q5elDHq5hmjhG99XHYXaIj2YXCZiipiTn05Km+EmiPB2tkwiO+yLcNSYl cmQpLQuSrlLXL83njLqjiSxEkHZl/nx09sFVxQM7YMQZULs495ztqeUBqZu4xLqA U8jVU7tkuRnnTYBAJnISfwuY5/Ui709a58svxXA4mGrL+EqAO7EzlNOX7jdmowf3 1f39iVS5A7yO0HLFF3hQOdrJWpfKTEuS5ajXFnOmopHmAdC8XtwwL9ykMXLLHbro ep34F9yirDo= =YjqN -----END PGP SIGNATURE----- --Sig_/yLBZ7szx3Uykn8uZjTJ3m5P--