At Wed, 16 Feb 2011 12:00:27 -0500 (EST) CentOS mailing list <centos at centos.org> wrote: > > We have about 50 CentOS servers with software RAID level 1 (mirroring). > Each week, we swap out one of the drives (the one in the second of four > hot-swap bays, only the first two of which contain drives) on each server > and take them offsite for safekeeping. > > The problem is, the kernel seemingly randomly switches between /dev/sdb > and /dev/sdc for these devices. This makes the process slower by > requiring more manual input where a script(s) could otherwise suffice. I'm assuming these are actually SATA disks with a controller that supports hot-swap. What I think is happening is that the kernel retains some 'memory' of the pulled drive (say /dev/sdb) and when the fresh drive is installed, a new dev file is created (/dev/sdc). Eventually, /dev/sdb is forgotten by the time the next 'swap' and /dev/sdb is assigned to the next fresh disk. Question: are you always swapping in a *new* disk each week or re-inserting the disk from the previous week? > > It also confuses smartd, which AFAIK, needs the correct device names to > report accurately. > > Ideally, we'd like to force the OS at some level to always see these > devices as /dev/sda and /dev/sdb. If not, is there at least some way to > configure smartd to be "smart" and recognize which devices are in use? The cure might be that you need to do a reboot to properly rescan the disks. > > TIA, > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > -- Robert Heller -- 978-544-6933 / heller at deepsoft.com Deepwoods Software -- http://www.deepsoft.com/ () ascii ribbon campaign -- against html e-mail /\ www.asciiribbon.org -- against proprietary attachments