Hi,
I've been doing some testing of wiping file systems, either using the
wipefs command or by writing zeros over the whole partition, and find
that in many distribution / parted version combinations it prints the
type of the file system that use to be there, even after formatting with
a new file system. I'm doing this for a GParted patch I am working on.
Can anybody explain the behaviour and how to fix it?
Thanks,
Mike
Details of more tested combinations in:
GNOME Bug 688882 - Improve clearing of file system signatures
https://bugzilla.gnome.org/show_bug.cgi?id=688882
Failing example on my Fedora 17 box with parted 3.1 (from Fedora 18
beta):
Create a new partition and format it with jfs. Write zeros over the
partition, reformat it as ext2, yet parted still reports the type as
jfs.
# parted /dev/sda print
Model: ATA SAMSUNG SSD 830 (scsi)
Disk /dev/sda: 128GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 1049kB 525MB 524MB primary ext4 boot
2 525MB 2673MB 2147MB primary linux-swap(v1)
3 2673MB 13.4GB 10.7GB primary ext4
4 13.4GB 121GB 107GB extended
5 13.4GB 77.8GB 64.4GB logical ext3
6 77.8GB 78.4GB 524MB logical ext4
7 78.4GB 80.5GB 2147MB logical linux-swap(v1)
8 80.5GB 91.2GB 10.7GB logical ext4
9 91.2GB 91.8GB 524MB logical ext4
10 91.8GB 93.9GB 2147MB logical linux-swap(v1)
11 93.9GB 105GB 10.7GB logical ext4
12 105GB 106GB 1074MB logical jfs
# dd if=/dev/zero of=/dev/sda12 bs=1M
# parted /dev/sda print
...
12 105GB 106GB 1074MB logical jfs
# mkfs.ext2 /dev/sda12
# wipefs /dev/sda12
offset type
----------------------------------------------------------------
0x438 ext2 [filesystem]
UUID: 5fe4cc76-61be-4878-b337-b4c5c155fb0c
# parted /dev/sda print
...
12 105GB 106GB 1074MB logical jfs
