The reason for the udev hotplug rule is simply for the purpose of mounting removable devices as read-only. If udev is left to its devices, everything plugged up is read-write which is verboten in this application. Unfortunately, there seems to be no way (i've found) to distinguish, at device/bus level, between a system HDD, a hardware RAID volume and an eSATA device and handle the eSATA device uniquely from others. All eSATA and USB devices _must_ mount read-only. If everything is lined up at boot, sda and sdb are camped via fstab and udev deals with sdc and above, mounting what are known to be removable devices as r/o. Shotgun, i know, but there is no way of knowing in advance what devices the system (er, appliance) will see. tangled, huh? thanks - csawyer Robert Heller heller at deepsoft.com Thu Mar 31 14:20:55 EDT 2011 Previous message: CentOS Digest, Vol 74, Issue 31 Next message: figuring out LogVol details for mount Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] At Thu, 31 Mar 2011 18:23:00 +0100 CentOS mailing list <centos at centos.org> wrote: > > thanks for the reply, Phil > > It would, were udev not inserting USB and/or eSATA drives at /dev/sdb1 > and/or /dev/sdc1 and exposing the array to the udev rule intended to > handle only removable devices (at sdc or sdd). The array then mounts > unpredictably in /media/xxx-sdc1 or sdd1 - not what is wanted - depend > on how many removable devices are plugged at the time of rebooting. Of > course, a single removable device will camp at sdb, which is out of > reach of udev so the whole hotplug thing is broken until someone removes > all of the devices at site, allowing a clean boot. Do you have some *nonstandard* udev rule for hot plug devices? The *standard* hotplug udev rules are not tied to specific ranges of sdXX's -- my IDE-based laptop will properly handle a hot plugged USB device at /dev/sda for example. The hot plug logic should also not mess with not hot pluged devices. If your RAID array is mounted in /etc/fstab (or has a 'noauto' line in /etc/fstab with the idea of mounting it manually later or has something in automount's config for automounting it), the hot plug system should not touch it, no matter what /dev/sdXX it happens to land at, so long as you are using volume labels or some such to reference the mountable volumes. - cal sawyer _______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos