Carl Lowenstein wrote:
But if I reboot the system, the USB drives are not available at the time that the startup process probes LVM devices, and thus not available for fsck and mounting. So the system comes to the error screen "enter root password to repair". And I can't repair it from there because the last part of the repair process is rebooting.
I had this problem happen a couple times when creating a box to use for disk-to-disk backups. What I ended up doing is adding a couple wait states into the init scripts. I think I added a 10 second wait between the time that the /sbin/init was called from the ramdisk, and the time that the /sbin/init script calls the lvm tools to make the volumes available. It's not ideal, but it worked.
The problem is that the USB Storage driver has some issues waiting for disks to acquiesce before scanning them. So, it puts the process into a kernel thread and allows the rest of the system to continue booting. Usually, by the time the disks are ready to be mounted, they've settled. Unfortunately, the LVM step is before this so that doesn't quite work out. Classic example of a race condition.
I submitted a feature request to the usb-storage maintainer to have the desired behaviour (wait to settle then scan in the same thread), but I never heard anything back from him. He may have fixed it by now and added an option to not spawn the thread.
Note that this is not a permanent condition, and will be cured by moving the new disk to its home in the CPU box.
yay for LVM! :) -kelsey -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
