Hello,
I was playing with btrfs and accidentally formatted the disk directly
(/dev/sdb instead of sdb1). Since then I rewrote the GPT partition
table, recreated the partition and ran btrfs device scan. Still, btrfs
filesystem show prints:
root@horus /mnt # btrfs fi sh --all-devices
failed to read /dev/sr0: No medium found
Label: ''test'' uuid: ffab72f2-eff1-4ac8-a694-d56dd84fda24
Total devices 1 FS bytes used 28.00KB
devid 1 size 2.73TB used 2.04GB path /dev/sdb
Label: ''home'' uuid: c465d715-098a-4d0d-bebc-6aa51f4cb349
Total devices 1 FS bytes used 28.00KB
devid 1 size 2.73TB used 2.04GB path /dev/sdb1
Btrfs Btrfs v0.19
Label home is the actual partition in use but how can I get rid of
label test which was the accidental formatting? Is this just some
cached value or still persistent on the disk?
Thanks,
Florian
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Hallo, Florian, Du meintest am 05.08.12:> I was playing with btrfs and accidentally formatted the disk directly > (/dev/sdb instead of sdb1). Since then I rewrote the GPT partition > table, recreated the partition and ran btrfs device scan. Still, > btrfs filesystem show prints:> root@horus /mnt # btrfs fi sh --all-devices > failed to read /dev/sr0: No medium found > Label: ''test'' uuid: ffab72f2-eff1-4ac8-a694-d56dd84fda24 > Total devices 1 FS bytes used 28.00KB > devid 1 size 2.73TB used 2.04GB path /dev/sdb> Label: ''home'' uuid: c465d715-098a-4d0d-bebc-6aa51f4cb349 > Total devices 1 FS bytes used 28.00KB > devid 1 size 2.73TB used 2.04GB path /dev/sdb1"formatting" leaves most bytes on the disk untouched. If you really want to use only /dev/sdb (or only /dev/sdb1) then you should first fill many bytes at the beginning of the disk with zeros. Some months ago someone had told the minimum; I have forgotten this value. But something like dd if=/dev/zero of=/dev/sdb bs=1M count=10 should do the job. And then "mkfs.btrfs" creates the (only) wanted partition(s). Viele Gruesse! Helmut -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am Sonntag, 5. August 2012 schrieb Florian Lindner:> Hello,Hi Florian,> I was playing with btrfs and accidentally formatted the disk directly > (/dev/sdb instead of sdb1). Since then I rewrote the GPT partition > table, recreated the partition and ran btrfs device scan. Still, btrfs > filesystem show prints: > > root@horus /mnt # btrfs fi sh --all-devices > failed to read /dev/sr0: No medium found > Label: ''test'' uuid: ffab72f2-eff1-4ac8-a694-d56dd84fda24 > Total devices 1 FS bytes used 28.00KB > devid 1 size 2.73TB used 2.04GB path /dev/sdb > > Label: ''home'' uuid: c465d715-098a-4d0d-bebc-6aa51f4cb349 > Total devices 1 FS bytes used 28.00KB > devid 1 size 2.73TB used 2.04GB path /dev/sdb1wipefs shows and removes filesystem signatures. No need to dd. Ciao, -- Martin ''Helios'' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am Sonntag, 5. August 2012 schrieb Florian Lindner:> Hello,Hi Florian,> I was playing with btrfs and accidentally formatted the disk directly > (/dev/sdb instead of sdb1). Since then I rewrote the GPT partition > table, recreated the partition and ran btrfs device scan. Still, btrfs > filesystem show prints: > > root@horus /mnt # btrfs fi sh --all-devices > failed to read /dev/sr0: No medium found > Label: ''test'' uuid: ffab72f2-eff1-4ac8-a694-d56dd84fda24 > Total devices 1 FS bytes used 28.00KB > devid 1 size 2.73TB used 2.04GB path /dev/sdb > > Label: ''home'' uuid: c465d715-098a-4d0d-bebc-6aa51f4cb349 > Total devices 1 FS bytes used 28.00KB > devid 1 size 2.73TB used 2.04GB path /dev/sdb1wipefs shows and removes filesystem signatures. No need to dd. Ciao, -- Martin ''Helios'' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html