Can we change disk label ( using fdisk or parted utility) of a diks from msdos/linux to GPT without losing data?
Say we have a 10 GB disk, having disk label msdos(Linux or hex code 83) and that has ext3 filesystem on 1 GB primary partition.
Here is test output and explanations
Create a 1 GB partition using fdisk label hex code 83 (Linux)- parted detects it as msdos label
# fdisk -l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
#
# fdisk -l /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-10240, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-10240, default 10240): +1G
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
# fdisk /dev/sdb[3@-l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 83 Linux
Create ext3 filesystem on 1G partition created by fdisk, mount it, copy some dummy data and take note of number of files / total size
# mkfs.ext3 /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
warning: 252 blocks unused.
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
65664 inodes, 262144 blocks
13119 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=268435456
8 block groups
32768 blocks per group, 32768 fragments per group
8208 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Writing inode tables: 0/81/82/83/84/85/86/87/8done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 20 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
#
# mkdir /dummyfs
# mount /dev/sdb1 /dummyfs
# cp -a /etc/* /dummyfs/
# ls -lR /dummyfs|wc -l
2465
# du -sh /dummyfs
27M /dummyfs
Unmount it and cahnge disklabel to hex code ee (GPT )
# umount /dummyfs
#
fdisk -l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 83 Linux
# fdisk -l /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): L
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32m 85="" boot="" c7="" extended="" font="" inux="" nbsp="" prep="" yrinx="">
5 Extended 42 SFS 86 NTFS volume set da Non-FS data
6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt
9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access
a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 63="" ab="" arwin="" boot="" f2="" font="" hurd="" nbsp="" or="" secondary="" sys="">
16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT
1e Hidden W95 FAT1
Hex code (type L to list codes): ee
Changed system type of partition 1 to ee (GPT)
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 ee GPT
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
# fdisk -l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 ee GPT
After changing label from hexcode type 83 ( Linux ) to GPT, mount did not recognoze filesystem type and not able to mount. Did you loose your data?!! Hold one a second !!
# mount /dev/sdb1 /dummyfs/
mount: you must specify the filesystem type
# mount -t ext3 /dev/sdb1 /dummyfs/
mount: special device /dev/sdb1 does not exist
Now change disk label back to hexcode 83 (Linux) from GPT ( hex code ee), mount filesystem and your data is there ! Conclusion: Changing disk label using fdisk from msdos/Linux to GPT will preserve data but you will be not able to mount - hence effectively unusable ( I do not know if there is any way to mount it ! )
# fdisk -l /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 83
Changed system type of partition 1 to 83 (Linux)
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
# fdisk /dev/sdb
#mount -t ext3 /dev/sdb1 /dummyfs
# ls -lR /dummyfs|wc -l
2465
#
du -sh /dummyfs
27M /dummyfs
Now change disk label from Linux (83) to Linux LVM (8e). You will be able to mount it. Conclusion : Changing label from 83 to 8e preserve data and allow to mount filesystem.
# umount /dummyfs
# fdisk /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 8e
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
#
mount /dev/sdb1 /dummyfs# ls -lR /dummyfs|wc -l
2465
#
du -sh /dummyfs
27M /dummyfs
Changing label using parted - result loss of partition information in parted print output !!
# umount /dummyfs/
# parted
GNU Parted 2.1
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) select /dev/sdb
Using /dev/sdb
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 16.4kB 1075MB 1075MB primary ext3 lvm
(parted) mklabel
New disk label type? gpt
Warning: The existing disk label on /dev/sdb will be destroyed and all data on this disk will be lost. Do you want to continue?
Yes/No? Yes
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
( nothing printed here )
(parted) rescue
Start? 16.4kB
End? 1075MB
searching for file systems... 3% (time left 00:27)
searching for file systems... 97% (time left 00:00)
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
( nothing printed here )
(parted) quit
Information: You may need to update /etc/fstab.
fdisk still recognize partition as GPT, but you will not be able to mount it.
# fdisk -l /dev/sdb
WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 1 1306 10485759+ ee GPT
# mount /dev/sdb1 /dummyfs
mount: you must specify the filesystem type
# mount /dev/sdb1 /dummyfs-t ext3
mount: special device /dev/sdb1 does not exist
So, once disk label has been changed to GPT using parted, parted do not list partition at all but fdisk still recognize it at GPT.
# parted
GNU Parted 2.1
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) / select /dev/sdb
Using /dev/sdb
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
(parted) quit
#
I am sure there will be some way to deal with using parted or cfdisk or some other utility. Do let me know if you know it.
Say we have a 10 GB disk, having disk label msdos(Linux or hex code 83) and that has ext3 filesystem on 1 GB primary partition.
- Short answer is NO
- Long answer is also NO. On my test system, changing label using fdisk preserve data byt filesystem is not longer mountable. Changing label using parted is complete damage - no data and no mounting !!
Here is test output and explanations
Create a 1 GB partition using fdisk label hex code 83 (Linux)- parted detects it as msdos label
# fdisk -l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
#
# fdisk -l /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-10240, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-10240, default 10240): +1G
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
# fdisk /dev/sdb[3@-l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 83 Linux
Create ext3 filesystem on 1G partition created by fdisk, mount it, copy some dummy data and take note of number of files / total size
# mkfs.ext3 /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
warning: 252 blocks unused.
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
65664 inodes, 262144 blocks
13119 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=268435456
8 block groups
32768 blocks per group, 32768 fragments per group
8208 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Writing inode tables: 0/81/82/83/84/85/86/87/8done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 20 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
#
# mkdir /dummyfs
# mount /dev/sdb1 /dummyfs
# cp -a /etc/* /dummyfs/
# ls -lR /dummyfs|wc -l
2465
# du -sh /dummyfs
27M /dummyfs
Unmount it and cahnge disklabel to hex code ee (GPT )
# umount /dummyfs
#
fdisk -l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 83 Linux
# fdisk -l /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): L
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32m 85="" boot="" c7="" extended="" font="" inux="" nbsp="" prep="" yrinx="">
5 Extended 42 SFS 86 NTFS volume set da Non-FS data
6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt
9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access
a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 63="" ab="" arwin="" boot="" f2="" font="" hurd="" nbsp="" or="" secondary="" sys="">
16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT
1e Hidden W95 FAT1
Hex code (type L to list codes): ee
Changed system type of partition 1 to ee (GPT)
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 ee GPT
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
# fdisk -l /dev/sdb
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 ee GPT
After changing label from hexcode type 83 ( Linux ) to GPT, mount did not recognoze filesystem type and not able to mount. Did you loose your data?!! Hold one a second !!
# mount /dev/sdb1 /dummyfs/
mount: you must specify the filesystem type
# mount -t ext3 /dev/sdb1 /dummyfs/
mount: special device /dev/sdb1 does not exist
Now change disk label back to hexcode 83 (Linux) from GPT ( hex code ee), mount filesystem and your data is there ! Conclusion: Changing disk label using fdisk from msdos/Linux to GPT will preserve data but you will be not able to mount - hence effectively unusable ( I do not know if there is any way to mount it ! )
# fdisk -l /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 83
Changed system type of partition 1 to 83 (Linux)
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
# fdisk /dev/sdb
#mount -t ext3 /dev/sdb1 /dummyfs
# ls -lR /dummyfs|wc -l
2465
#
du -sh /dummyfs
27M /dummyfs
Now change disk label from Linux (83) to Linux LVM (8e). You will be able to mount it. Conclusion : Changing label from 83 to 8e preserve data and allow to mount filesystem.
# umount /dummyfs
# fdisk /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): 8e
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
64 heads, 32 sectors/track, 10240 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a652f
Device Boot Start End Blocks Id System
/dev/sdb1 1 1025 1049584 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
#
mount /dev/sdb1 /dummyfs# ls -lR /dummyfs|wc -l
2465
#
du -sh /dummyfs
27M /dummyfs
Changing label using parted - result loss of partition information in parted print output !!
# umount /dummyfs/
# parted
GNU Parted 2.1
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) select /dev/sdb
Using /dev/sdb
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 16.4kB 1075MB 1075MB primary ext3 lvm
(parted) mklabel
New disk label type? gpt
Warning: The existing disk label on /dev/sdb will be destroyed and all data on this disk will be lost. Do you want to continue?
Yes/No? Yes
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
( nothing printed here )
(parted) rescue
Start? 16.4kB
End? 1075MB
searching for file systems... 3% (time left 00:27)
searching for file systems... 97% (time left 00:00)
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
( nothing printed here )
(parted) quit
Information: You may need to update /etc/fstab.
fdisk still recognize partition as GPT, but you will not be able to mount it.
# fdisk -l /dev/sdb
WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 1 1306 10485759+ ee GPT
# mount /dev/sdb1 /dummyfs
mount: you must specify the filesystem type
# mount /dev/sdb1 /dummyfs-t ext3
mount: special device /dev/sdb1 does not exist
So, once disk label has been changed to GPT using parted, parted do not list partition at all but fdisk still recognize it at GPT.
# parted
GNU Parted 2.1
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) / select /dev/sdb
Using /dev/sdb
(parted) p
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
(parted) quit
#
I am sure there will be some way to deal with using parted or cfdisk or some other utility. Do let me know if you know it.
I know this is an older post but in case someone comes across and it and wants to know: yes it can be done!
ReplyDeleteI had formatted a 4TB drive using a repurposed USB bridge from a Seagate Backup Plus external enclosure (the original drive had died so I took it apart).
I had trouble aligning the partition and such but that is another story. When I installed the drive into the system using the native SATA, the system had trouble recognizing the partition. It never occurred to me that the USB Bridge was translating the drive CHS. It presented the drive as 4096 sized sectors when in reality it is 512 sized. The system partitioned the drive as msdos when on the USB Bridge. This caused problems when hooked up to SATA connection on the system because msdos partition labels do not support drives larger than 2TB. I was unable to mount the 4TB EXT4 filesystem on the drive. When I finally had the partition visible to the OS, it had chopped the partition in half due to the 2TB limit.
After much searching I found a post that fixed the problem using a combination of gpart and testdisk. It fixed my issues of an insufficient msdos label which was successfully migrated to GPT; all data safe and sound, happy to say.
https://serverfault.com/questions/764271/cant-mount-sata-drives-when-moved-from-usb-enclosure-to-internal
Thanks!