From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Hill Subject: Re: auto-read-only question Date: Fri, 25 Feb 2011 16:26:32 +0000 Message-ID: <20110225162632.GD11345@cthulhu.home.robinhill.me.uk> References: <4D67D3D4.9040306@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tThc/1wpZn/ma/RB" Return-path: Content-Disposition: inline In-Reply-To: <4D67D3D4.9040306@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Albert Pauw Cc: "linux-raid@vger.kernel.org" List-Id: linux-raid.ids --tThc/1wpZn/ma/RB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri Feb 25, 2011 at 05:07:48PM +0100, Albert Pauw wrote: > Can anybody explain to me what "active (auto-read-only)" mean in=20 > /proc/mdstats? >=20 When the array is assembled, it's set in "auto-read-only" mode. As soon as anything tries to write to it, it gets set to normal write mode (or you can trigger this manually by doing "mdadm -w" on the array). I'm not sure why this is done - possibly it make it simpler for md to skip running various internal processes on that array (as it knows that the array isn't being dirtied). I usually see this with swap arrays - most filesystems will immediately open the array in read/write mode, so trigger the switch. Cheers, Robin --=20 ___ =20 ( ' } | Robin Hill | / / ) | Little Jim says .... | // !! | "He fallen in de water !!" | --tThc/1wpZn/ma/RB Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) iEYEARECAAYFAk1n2DYACgkQShxCyD40xBKeIwCcDx2irjuEHp8NI/Qf5v7GVX+b lGIAoIegB8J/wgDEYByU2XmEy/dxnA3P =4I25 -----END PGP SIGNATURE----- --tThc/1wpZn/ma/RB--