(CCs trimmed) Anthony Youngman wrote: > > > On 07/10/16 18:44, Dark Penguin wrote: > > > >I actually wanted to ask about that. Can you really ddrescue a drive > >with a "hole" in it, re-add it and expect it to work?.. What happens if > >you try to read from that "hole" again? And while I'm talking about > >re-adding, when does it become impossible to "re-add" a drive?.. > > If you want to do some kernel development work, this is something > you can do something about :-) > > ddrescue creates a log of sectors that failed to copy. I've been > thinking a bit about this, not least because other people have > mentioned it. I've done disk rescues where I work and I came up with an idea to use the device mapper targets to emulate this. Why not just read the .log file and create a mapping where if it's good, it goes to the disk, if bad, it goes to error. It obviously won't handle writes, but you can layer a snapshot device on top of it. When the "error" is corrected, it'll write to the snapshot. You can then tear everything down, and merge the snapshot into the disk. I tried something similar when I had a bad sector on a drive and md kept kicking it out. Fortunately it was in /usr and wasn't important. -- Microsoft has beaten Volkswagen's world record. Volkswagen only created 22 million bugs. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
