On Mon, Nov 15, 2010 at 4:47 PM, Lars Ellenberg <lars.ellenberg@linbit.com> wrote: > On Mon, Nov 15, 2010 at 02:53:29PM -0500, Stirling Westrup wrote: >> On Sun, Nov 14, 2010 at 6:52 PM, Stirling Westrup <swestrup@gmail.com> wrote: >> >> >> > Thanks for going through all those steps. It does make the procedure a >> > lot clearer in my mind, and it does look like dd_rescue is the way to >> > go then. I'm going to head off to try it now. >> > >> >> Okay, I've tried the dd_rescue method that was outlined for me, and it >> failed, although not for any reasons inherent in the method. It seems >> that what is wrong with my 'flakey' drive is not that it has bad >> sectors, but that it has a tendency to heat up when used, and then >> fail all operations until its cooled down. > > You can hook up your old drive to the external sata, > and point a fan right at it, > or even use a long eSATA cable and put it in the fridge. No joke, this > has been done to successfully recover data from failing drives. I don't have a cable long enough to try the fridge trick, but I'm going to try a fan, and maybe rest it on a metal container full of ice. If it works, this might make the rest of my questions a bit redundant, but still... > I find useful: > # lvs -o +seg_pe_ranges > Aha! Thanks. That's just what I was hoping for. Again, I was looking for a pv_ option, not an lg_ one, as I assumed that PEs were the purview of the physical volume layer. >> 2) how often are checkpoints made, and can you control that in any way? > > IIRC, pvmove does one PE at a time, > and will checkpoint each of these. > Depending on wether or not you set the PE size explicitly on vgcreate > time, this frequent checkpointing every few MB may slow down things. I didn't set my PE size explicitly, so I checked in /etc/lvm/backup and it looks like I have 4mb extents. This should mean that I'm making significant progress every time I attempt to continue the pvmove. Now, is there any way to monitor that progress? Every time I issued a bare 'pvmove' to continue the operation, it starts counting from 0% again. I'm assuming (hoping!) this is a percentage of the amount LEFT to move, not the total amount that needs to be moved, but I'd love some way to verify this. > pvmove /dev/sda:7-9 /dev/sde:7-9 Okay. What if I don't care where the PE's end up? Can I just say: pvmove /dev/sda:1000-1500 /dev/sdb and assume it will do something reasonable? I currently don't have any fragmentation anywhere, so I would hope this would just work. > Does that make sense? Yes, it does. You've been extremely helpful so far. -- Stirling Westrup Programmer, Entrepreneur. https://www.linkedin.com/e/fpf/77228 http://www.linkedin.com/in/swestrup http://technaut.livejournal.com _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
