Rich Shepard <[email protected]> writes: > I've searched with Google but despite headings that imply how to find the > UUID of a specific device, the page contents do not really tell me how to do > this.
You had it *almost* right, too. > In /etc/fstab the entry for my external backup disk is > UUID=436bc83a-1d2b-4c58-b3a9-5dbe8efc4112 /media/hd0 ext3 defaults 0 0 > > The past couple of mornings I see a mail message that the dirvish backup > could not unmount the drive. When I tried from the command line this morning > the attempt failed because the UUID did not match what the kernel saw. > Turning off the drive, and back on about a hour later allowed me to umount > the drive. > > How do I determine the UUID for devices such as this external drive? I've > tried 'vol_id', but 'vol_id -u /media/hd0' responds that it's an unknown or > unique media type and I see the same response if I use --uuid as the option > to vol_id. /media/hd0 is the *mount* point for the filesystem, not the device. Tools like blkid and vol_id need to look at the raw disk itself. That means you want: blkid /dev/sda1 # or whatever raw device it is at. [...] Rich Shepard <[email protected]> writes: > On Fri, 29 Oct 2010, Gerald Turner wrote: > >> Could the problem be that you've changed your external drive to vfat? > > Not unless it was the rainy weather. It's ext3. Also, you would still get identifying information out of it. :) >> I just tried a USB stick formatted with vfat, at first 'blkid' didn't >> report any information for it (maybe blkid is using a cache, or maybe it's >> ignoring vfat partitions), but then ran 'blkid -p /dev/sdg1' ("low-level >> probe") and it reported the UUID and other attributes just fine and >> mysteriously, subsequently running just 'blkid' now reports the data. > > Huh! I did not know this tool existed. It's here, too, on Slackware. > Running just 'bklid' with no dev specified found all partitions and returned > the UUID and filesystem type. O_o How odd. I didn't know blkid did any caching. :) Daniel -- ✣ Daniel Pittman ✉ [email protected] ☎ +61 401 155 707 ♽ made with 100 percent post-consumer electrons _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
