cleaning signatures off disks

Tripped over an issue recycling a disk using LVM

WARNING: dos signature detected on /dev/disk/by-id/ata-TOSHIBA_MK6459GSX_X9QCF7BGS at offset 510. 
Wipe it? [y/n]: [n]
Aborted wiping of dos.
1 existing signature left on the device.

This came from (failed) volume group creation within a puppet run.


There’s a tool called wipefs which fixes this.  I’d like to see how this handles disks with bits of LVM still on them.

It’s in the minimal raspberry pi Centos 7 build as well, which was a nice bonus.

The linked page above specifies then passing ‘–all’ and ‘–force’ but every time I see the force being used (use the Force, Luke) I want to understand why, and ideally avoid it.

# wipefs /dev/disk/by-id/ata-TOSHIBA_MK6459GSX_X9QCF7BGS
offset type
0x1fe dos [partition table]

# wipefs --help

wipefs [options] <device>

-a, --all wipe all magic strings (BE CAREFUL!)
-f, --force force erasure
-h, --help show this help text
-n, --no-act do everything except the actual write() call
-o, --offset <num> offset to erase, in bytes
-p, --parsable print out in parsable instead of printable format
-q, --quiet suppress output messages
-t, --types <list> limit the set of filesystem, RAIDs or partition tables
-V, --version output version information and exit

# wipefs --offset 0x1fe /dev/disk/by-id/ata-TOSHIBA_MK6459GSX_X9QCF7BGS
/dev/disk/by-id/ata-TOSHIBA_MK6459GSX_X9QCF7BGS: 2 bytes were erased at offset 0x000001fe (dos): 55 aa
/dev/disk/by-id/ata-TOSHIBA_MK6459GSX_X9QCF7BGS: calling ioclt to re-read partition table: Success

There, no need to go to the dark side.



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