cleaning old entries
Hallo, linux-btrfs,
on my testing USB stick
btrfs fi show
shows
Label: 'mylabel' uuid: e9716633-49f1-44a0-a3b4-90ba9736a540
Total devices 3 FS bytes used 28.00KB devid 3 size 1.00GB used 288.00MB path /dev/sdb3 devid 2 size 1.00GB used 512.00MB path /dev/sdb2 devid 1 size 1.00GB used 292.00MB path /dev/sdb1
Label: 'USBmm' uuid: 43ad1782-5d1c-4211-9333-506bcfdbc3a5
Total devices 1 FS bytes used 28.00KB devid 1 size 3.78GB used 423.50MB path /dev/sdb
Btrfs Btrfs v0.19
# ----------------------------------------------------
The problem entry is "Label: 'USBmm'
It is a remainder of an older experiment, with 2 sticks, configured with
mkfs.btrfs -d raid0 -m raid1 -L USBmm /dev/sdb /dev/sdc
And at least the label "USBmm" resides somewhere on the stick where it is hidden from manipulations (except something like "dd if=/dev/zero ...")
A bit more precisely: the label lies at the beginning of the second 64- kByte block on the stick (may be sector 129). Far away from the other partition data.
Contents of "/proc/partitions":
major minor #blocks name
8 0 29302560 sda 8 1 9775521 sda1 8 2 369495 sda2 8 3 4891792 sda3 8 4 14265720 sda4 11 0 1048575 sr0 8 16 3968000 sdb 8 17 1048576 sdb1 8 18 1048576 sdb2 8 19 1048576 sdb3 8 20 821248 sdb4
# ------------------------------------------
Output from "fdisk -l /dev/sdb":
Platte /dev/sdb: 4063 MByte, 4063232000 Byte
125 Köpfe, 62 Sektoren/Spur, 1024 Zylinder, zusammen 7936000 Sektoren Einheiten = Sektoren von 1 ₧ 512 = 512 Bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x266cff07
Gerät boot. Anfang Ende Blöcke Id System
/dev/sdb1 2048 2099199 1048576 83 Linux /dev/sdb2 2099200 4196351 1048576 83 Linux /dev/sdb3 4196352 6293503 1048576 83 Linux /dev/sdb4 6293504 7935999 821248 83 Linux
# ------------------------------------------
findfs LABEL=USBmm
says "unable to resolve 'LABEL=USBmm'" - that's ok.
And
blkid
tells nothing about "/dev/sdb" - that's also ok.
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Has "mkfs.btrfs" to delete the "/dev/sdb" data when it overwrites the configuration with data for partitions? Or has the user to run something like "dd if=/dev/zero ..."?
Viele Gruesse!
Helmut
Quoted 3 lines · Helmut Hullen
Has "mkfs.btrfs" to delete the "
/dev/sdb" data when it overwrites the configuration with data for partitions? Or has the user to run something like "dd if=/dev/zero ..."?
Take a look at:
https://btrfs.wiki.kernel.org/index.php/Problem_FAQ#How_to_clean_up_old_superblock_.3F
Hallo, Jan,
Du meintest am 05.01.13:
Quoted 7 lines
Quoted 3 lines
Has "mkfs.btrfs" to delete the "
/dev/sdb" data when it overwrites the configuration with data for partitions? Or has the user to run something like "dd if=/dev/zero ..."?Take a look at:
https://btrfs.wiki.kernel.org/index.php/Problem_FAQ#How_to_clean_up_o
ld_superblock_.3F
Thank you - "wipefs" may help.
Viele Gruesse!
Helmut