On 02/10/2013 01:32 AM, Piotr Pawłow wrote: > Hello, >> Yeah you can't mount images, we clear out the chunk tree so >> nothing works. Let me know if you run into any problems in the >> future. Thanks, > > That's surprising, I haven't seen it mentioned anywhere. > > With any other filesystem I could use an LVM snapshot to save the > original state, but with a multi-device btrfs it would be very > risky. Origin and snapshot volumes could easily get mixed up by > kernel and tools. > > I tried that in qemu, and I've seen btrfs happily mount 1 origin and > 1 snapshot device as a single FS. And then I've seen it mount both > origin devices, even though one of them had old content. Naturally > it complained a lot about bad checksums. I can confirm that, even with a single-device btrfs filesystem. However I am curious why you want to use the lvm snapshot capability instead of the btrfs one. > > Is there any way to avoid such mix-ups? To somehow mark devices so > that btrfs would know these devices belong together? Btrfs assume that every device has an "unique" uuid. However when a device is snapshotted it uuid is copied too, so it is not unique any more. This is the reason of the btrfs confusing. > Regards -- To unsubscribe from this list: send the line "unsubscribe > linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 ss -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
