Date: Tue, 19 Sep 2006 11:25:34 -0500 From: "M. L. Dodson" <mldodson@houston.rr.com> To: John-Mark Gurney <gurney_j@resnet.uoregon.edu> Cc: freebsd-firewire@freebsd.org Subject: Re: devfs and hot unplugging firewire device Message-ID: <200609191125.35128.mldodson@houston.rr.com> In-Reply-To: <20060919160447.GC23915@funkthat.com> References: <200609191005.17015.mldodson@houston.rr.com> <20060919160447.GC23915@funkthat.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tuesday 19 September 2006 11:04, John-Mark Gurney wrote: > M. L. Dodson wrote this message on Tue, Sep 19, 2006 at 10:05 -0500: > > When I finished a dump/restore, I just pulled the cable (the > > firewire disk partitions were not mounted). When I plugged in the > > The problem is that the old devices still are open for writing.. If > you were to umount -f the old fs, most likely, the devices would > wither away, and things would be back to normal... > Hmmm... I just looked at the umount man page. I guess the behaviour you describe can be implied by it, but it is certainly not obvious (at least to me). So, if I understand you, if instead of "umount /mnt", I do "umount -f /mnt", the behaviour will be as I expected: the device will be completely unmounted and the device will disappear when I pull the cable? > I hope you were fsync'ing the files before you unmounted the disk > to ensure that the file was completely written to disk, otherwise > you could end up w/ the an incomplete file... > Actually, my sequence was: fsck the /dev/da0s1* (excluding b and c), and that was where I noticed the problem (on the second firewire disk in the sequence of 7 disks dumped), then dump the g partition to a file on the server's main disk. Then I did a restore -if <dumped to file> in the directory I wanted the stuff to go into. I did it this way so I could exclude some unimportant stuff that was in the /home directory on the firewire disk (corresponding to /dev/da0s1g). The only time I mounted the disk was to rsync between the firewire /home (/dev/da0s1g) and the restored data directory to check for errors. (This data cost weeks of computation for many of the files, so better to take a little time to wear belt AND suspenders). The firewire disk was only ever read from, not written to except for the fsck. Your answer implies to me that if I had never mounted the device it would have gone away when I pulled the cable. Right? > > My question: Should I be doing something to signal devfs I'm going > > to unplug a device so it won't get confused when I plug in another > > similar, but not the same, device? camcontrol commands like > > "camcontrol eject <options>" and "camcontrol rescan all" seemed to > > not have the results I expected. What's going on here? > > umount the file system... I unplug firewire drives that don't have > mounted filesystems, and haven't had an issue with it... OK, that is certainly what I get from your first couple of paragraphs. Thanks for the explanation! Bud Dodson -- M. L. Dodson Email: mldodson-at-houston-dot-rr-dot-com Phone: eight_three_two-56_three-386_one
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200609191125.35128.mldodson>