I wound up using kraduk's suggestion except for using a snapshot instead of a live file system. Because the source disk had suffered DMA errors and a few files lost to SOFT UPDATE errors, I built a full system first and then let rsync merge the two.
mount -u -o snapshot /snapshot/snap1 / mdconfig -a -t vnode -f /snapshot/snap1 -u 4 mount -r /dev/md4 /mnt mount /dev/ad4s1a /mnt_t rsync -aPH --exclude=usr/dumps/** /mnt/* /mnt_t umount /mnt mdconfig -d -u 4 umount /mnt_t repeated for all partitions (/ /tmp /var /usr). Also had to edit transferred fstab to reflect new device name (ad4) and install a new boot0. mount /dev/ad4s1a /mnt_t vi /mnt_t/etc/fstab umount /mnt_t fdisk -B -b /boot/boot0 /dev/ad4 18 GB took about 20 minutes to complete snapshots and another 25 minutes to transfer via rsync. Thanks for all the help. On Thu, 25 Jun 2009 10:49:50 -0500, Rick C. Petty wrote > On Wed, Jun 24, 2009 at 11:11:21PM +0100, krad wrote: > > Personally id stay away from dd. Create the partitions and file systems > > manually, and install the boot loader, then rsync the data across. It will > > be a lot faster in most cases, as unlike dd you wont be copying unused > > space. Something like this should do the job > > I wouldn't say rsync is faster than dd, unless you have a lot of > empty space or are migrating across a network. The nice thing about > rsync is it if you restart it, it picks up where it left off so to > speak. With dd you have to add two arguments. > > > Rsync -aPH --exclude=/mnt/** / /mnt > ^ > > I often use: > > rsync -avHSPx / /mnt > > The "x" means don't cross file system boundaries, which is generally > what you want when migrating file systems. > > > I'm assuming you weren't migrating due to a bad disk > > Actually using rsync to migrate a bad disk is preferrable over dd > > (presuming you have no backup), since rsync will skip and warn you aboud > bad files, but "dd conv=noerror" could leave you in a bad situation > if it skips over critical metadata blocks. I always try rsync first, > with the source filesystem mounted read-only, and if that fails > I'll fall back to dd. Actually if you have the space and it was a > bad disk, I'd probably dd to a new disk or file, then mount that > disk or file read-only, and then use rsync. > > -- Rick C. Petty > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean. -- Jim Flowers <[email protected]> _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
