Trouble swapping bootdisk to different controller

Matthew Dillon dillon at
Mon Jan 31 07:51:32 PST 2005

:> Some of the obstacles i experienced:
:> - /sbin not in PATH, why?
:It's a fallback value built into the shell and that doesn't
:include /sbin. Just add it.

    Actually, this has bitten me more then once.  The single user shell
    should include /sbin.  I'll go and fix it.

:> - weird device numbering: why can't the first disk be assigned to ad0???
:Because you have ATA_STATIC_ID in your kernel? Because the kernel doesn't
:know which "the first disk" is? Normally "internal" controllers are probed
:before "external" controllers, therefore "internal" disks are enumerated before
:"external" disks. Combine this with ATA_STATIC_ID and you get the behaviour
:you have.

    Note that ATA_STATIC_ID is the behavior I would recommend,
    especially for people constructing RAID volumes.  Otherwise if
    a disk goes missing a reboot might use the wrong disks to
    construct the volume.


    In anycase, what I usually do in a situation like this is boot
    from a live CD, which has a full environment, and then mount and fixup
    the hard drive from that.


More information about the Users mailing list