From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Keltz Subject: MD component device renaming with udev and MD on full disk Date: Fri, 21 Nov 2014 16:42:15 -0500 Message-ID: <546FB1B7.3050304@cse.yorku.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi. I have two questions about MD.. 1) I've written a udev rule to remap /dev/sdX devices on my system to /dev/cXeYsZpA (controller, enclosure, slot, partition) mapping. When I reboot the system, I see that all the devices in /dev are appropriately renamed. If I look at /proc/mdstat, it still has the kernel names of the devices (/dev/sdX) even though those devices no longer exist. If I do an mdadm --detail /dev/mdX the system reports the proper device name makeup. I manually failed a device, and I got the correct device name in the email. I'm just wondering what command I would execute to make /proc/mdstat update the devices in its output? 2) Unrelated to 1) -- the argument re: using MD on full devices versus partitions has been around for a long time. I've been experimenting with using it on full devices. One of the arguments that I've read for not using full devices is that apparently, if you have two devices that are identical, but one of them is slightly smaller than the other due to say, bad sectors, then these disks can't be used together in one MD because they are different sizes. I'm wondering how valid that argument is? Surely it would make sense if MD was using full devices for it to actually stop short of the end of the disk for situations like these... Thanks for any help you can provide. Jason.