On 19 September 2016 at 18:37, Robert McWilliam <r...@allmail.net> wrote: > On Mon, 19 Sep 2016, at 17:49, Colin Law wrote: >> On 19 September 2016 at 17:18, Robert McWilliam <r...@allmail.net> wrote: >> Is not the partition table in the space before the first partition? So >> in the example I posted where I had >> >> Device Boot Start End Sectors Size Id Type >> /dev/sdb1 8192 137215 129024 63M c W95 FAT32 (LBA) >> /dev/sdb2 137216 4233215 4096000 2G 83 Linux >> >> is not the partition table in sectors 0 to 8191? So if I copy sectors >> 0 to 2333215 that should include the partition table and all the >> partitions. Is that not correct? > > Put a 4 in front of that end sector number, lose one of the 3's, and > yes, I think you'd get partition table and those two partitions. That > kind of transcription error is why I don't think you should play with > offsets directly. That looks like a human transcription error so you > wouldn't have exactly that type of error in a script, but parsing text > to get a number is really fragile (what appears in the "Boot" column > there when it has something? Will your parsing be thrown off that? What > else might change?).
Indeed, that is precisely why I hoped there would either be better ways of determining the partion information or a better way of doing the whole exercise. > ... > For a whole card image you can make loopback devices for the partitions > in it: > $sudo losetup -Pf --show disk_image.raw > then mount the partitions > $sudo mount /dev/loop0p1 /mnt/point > then copy the files to a card (or anywhere else) with normal file > management tools, unmount the image: > $sudo umount /mnt/point > and detach the loopback device > $sudo losetup -d /dev/loop0 That is interesting, thanks. > > For the single partition image you don't need the loopback device and > can mount it directly with: > $sudo mount -o loop partition_image.raw /mnt/point > > As for partitioning the destination card: I'd keep them all partitioned > with one partition the full size of the card. If you want a clean card > to restore an image too: rm -rf /where/its/mounted (be very, very, > careful if putting that in a script with something to determine the > mount point...). I don't have full control of the partitions. The example I showed is is a bootable raspbian lite card. Another is a NOOBS card running raspbian, another is a SheevaPlug running Ubuntu 9.04 and so on. So if I want an automatic script it will have to clean and re-partition the new card appropriately. Regards Colin -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.ubuntu.com/UKTeam/
