Hello, I have a multi-device btrfs (with problems, more on that later). I looked into btrfs-image and was surprised to find that "for i in 5 6 7 8 ; do sudo btrfs-image -t2 /dev/sda$i - | md5sum;done" returns a different hash for sda7. The other three hashes are the same, as I believe they all should be, or am I mistaken?
$ for i in 5 6 7 8 ; do echo -n sda$i:" " ; sudo btrfs-image -t2 -c9 /dev/sda$i - | tee /tmp/sda$i.img | md5sum;done sda5: 047a1da23edeb9661e79d1006f17eab0 - sda6: 047a1da23edeb9661e79d1006f17eab0 - sda7: 9cc7afdc1476daa6f671db8d3c855164 - sda8: 047a1da23edeb9661e79d1006f17eab0 - $ sudo btrfs fi show Label: 'SSD128' uuid: f110a925-6ad9-4b40-9207-6bf09ce0cb23 Total devices 4 FS bytes used 105.96GiB devid 1 size 100.00GiB used 100.00GiB path /dev/sda5 devid 2 size 10.00GiB used 10.00GiB path /dev/sda6 devid 3 size 5.00GiB used 5.00GiB path /dev/sda7 devid 4 size 1.99GiB used 1.00GiB path /dev/sda8 The difference is somewhere very early on in the file: $ wc -c /tmp/sda?.img 223763456 /tmp/sda5.img 223763456 /tmp/sda6.img 223763456 /tmp/sda7.img 223763456 /tmp/sda8.img 895053824 total $ for file in /tmp/sda?.img;do echo -n $file: " "; tail -c 222950000 $file | md5sum;done /tmp/sda5.img: afe8010fa089415aaa55f2d549c3b5d4 - /tmp/sda6.img: afe8010fa089415aaa55f2d549c3b5d4 - /tmp/sda7.img: afe8010fa089415aaa55f2d549c3b5d4 - /tmp/sda8.img: afe8010fa089415aaa55f2d549c3b5d4 - $ for file in /tmp/sda?.img;do echo -n $file: " "; tail -c 222960000 $file | md5sum;done /tmp/sda5.img: 2bc5fe13e5f2dd8592a24eecb322482e - /tmp/sda6.img: 2bc5fe13e5f2dd8592a24eecb322482e - /tmp/sda7.img: ee26d34afa50ccb33e95e869b3e18af3 - /tmp/sda8.img: 2bc5fe13e5f2dd8592a24eecb322482e - How could this be? Regards Rolf PS: While I will check back for replies in the archive, a courtesy cc will be appreciated since I am not subscribed to the list. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html