From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: SES Enclosure Management. Date: Wed, 15 Feb 2012 08:16:11 +1100 Message-ID: <20120215081611.3cc31578@notabene.brown> References: <20120215073130.792d4fae@notabene.brown> <4F3AC828.5000202@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/Bp/AAilNl+U4c4_Y=7Yhumy"; protocol="application/pgp-signature" Return-path: In-Reply-To: <4F3AC828.5000202@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Robert Woodworth Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/Bp/AAilNl+U4c4_Y=7Yhumy Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Tue, 14 Feb 2012 13:46:32 -0700 Robert Woodworth wrote: > On 02/14/2012 01:31 PM, NeilBrown wrote: > > On Tue, 14 Feb 2012 10:30:37 -0700 Robert Woodworth > > wrote: > > > >> Has anyone ever thought of integrating SES managed enclosures into the > >> kernel RAID system? I briefly looked through the archives and have > >> not found anything on the topic. > >> > >> Some HW based RAID controllers do this flawlessly now, there is no > >> reason why the kernel RAID cannot also. (LSI MegaRAID) > >> > >> 1) When a drive is part if a managed enclosure, the RAID system should > >> address it by location instead of by enumerated device node. The SES > >> device in the enclosure can map the physical slot to a physical drive. > >> The RAID admin (mdamd) should be able to add/fail/identify devices > >> based on slot. > > Does this just mean that the admin should using names in /dev/disk/by-p= ath/ > > rather than /dev/sdXX to address devices? What can md or mdadm do to h= elp? > I don't like the /by-path/ too well, it is not human readable. I would=20 > propose that the SES module that is already in the base kernel be=20 > expanded to provide a /dev/disk/by-location// ->=20 > /dev/sdXY It isn't the kernel that provides these links, it is udev. If there is some tool that can extract the enclosureID and slot values, then one or 2 lines in a udev 'rules' file should be able to create the links. > > > The one piece that could be included in the kernel level is the display=20 > of /proc/mdstat to show the enclosureID and slot number I'm finding /proc/mdstat increasingly distasteful. It is very convenient b= ut hard to extend usefully. I' rather create something like mdadm --status which reported the status of all (or some) arrays with similar usability to /proc/mdstat, but more room to extend it. Thanks, NeilBrown --Sig_/Bp/AAilNl+U4c4_Y=7Yhumy Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBTzrPGznsnt1WYoG5AQIXdRAAvCNSDSwSNRDYQzL8l68qWqp7efXc1aTt 6BIeQBgioPcp6oiyXoiKF/GYGieWcORJCdv+bv8nrvUHbL+OU4NCfgoWFOmkXtFd NHdGUxqQgBY05g8fB8hqDhYPDX5FfYSNiVwi7fbK1g55fXuLNXQKGdzBwNgbN/iT LFegE+wPtMiXGwVaU6AUEhsEXPCHYo1+/5d6Zh0Tp1C6BiizaTPIoguVVw9H1jUu 8cZcOhKac5AVK7QCPcMBLNL1ucj/xSE287fAWNCmp7kTM4lUQZ+4Gq8pfnS2oR3b 82sUx87+VCO3yMs4NQQGhSD7/YLA09uMRwkS/FSgEHOXxCrAelo8a9tTXv/EOQZI rlxb+DsHNv5OYEl8PNpKKbCfFZrG6Wad6Wi9Y8t0YNiYF9+372wIn5PArtUqHYLj aKkpa07BzajZdIwu/p5I2VTSQibFDGTyXu46+ZQeI5Lvjdkf2kn21cFl8e1dCM+F hiYXAVRj6dhb5IZ3bQMutgVtZrAdc3FyMp00v02uAXAkgOqFRbq89VvHYl3ogYSb EwB7bqsJ3KA/Iqr6iXalC27lJxXyBrzHqo5BxD8ed1ksxhTJt4yNlej5NrviL0SX nyQbQ/wvmpBkZTO74msZxqkxAounBxkFqtUOxZH8jLu5i6uEL2xk3ku2Q9E57DNR CoQ8z/8tyXA= =Nqbb -----END PGP SIGNATURE----- --Sig_/Bp/AAilNl+U4c4_Y=7Yhumy--