From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Woodworth Subject: Re: SES Enclosure Management. Date: Tue, 14 Feb 2012 13:46:32 -0700 Message-ID: <4F3AC828.5000202@gmail.com> References: <20120215073130.792d4fae@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120215073130.792d4fae@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids 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-path/ > rather than /dev/sdXX to address devices? What can md or mdadm do to help? I don't like the /by-path/ too well, it is not human readable. I would propose that the SES module that is already in the base kernel be expanded to provide a /dev/disk/by-location// -> /dev/sdXY If you have ever worked with AIX, all devices have physical locations in the configurations held by the kernel. >> 2) If the RAID system fails a drive, it should notify the SES >> management and turn on the fail bit and the fail LED. > "mdadm --monitor" will run a script on drive failure. This could easily > notify the SES management. > > So maybe all we need here is a script to plug in to mdadm... Would you like > to write one? > Yes, I thought of that too. >> 3) The RAID system should be able to turn on the 'identify' bit and >> LEDs for an array or a single drive. > Again, it sounds like you just need a script to ask mdadm which devices are > included in a given array, and then do whatever magic is needed to turn on > the light. > It is fairly easy to extra the device list from the output of > mdadm --detail --brief --verbose /dev/md/whatever > > but it might be good to make it easier to extra from > mdadm --detail --export /dev/md/whatever > > Would you like to write such a script? Yes, I could take that on. >> I'm currently doing firmware on a managed enclosure. Although my >> vendor only supports LSI MegaRAID, there is no reason why my >> enclosures cannot work in the same manner on a kernel RAID system. >> >> >> >> Request for comments... > It sounds to me like you just need a few scripts to provide some > enclosure-specific functionality. I would be happy to include them in the > mdadm distribution. > > Or maybe there is something that I didn't understand?? > > Thanks, > NeilBrown > > The one piece that could be included in the kernel level is the display of /proc/mdstat to show the enclosureID and slot number >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html