need to convert MBR to GPT

SUSE Product Topics SLES Configure-Administer
1

Hi,
i have a FC SAN and just recognized that i can’t extend it anymore due to MBR’s limit of 2,2 TB.
So i need to change it to GPT.
This is the current layout:

[CODE]ha-idg-2:~ # parted /dev/mapper/3600c0ff00012824b04af7a5201000000
GNU Parted 3.1
Using /dev/mapper/3600c0ff00012824b04af7a5201000000
Welcome to GNU Parted! Type ‘help’ to view a list of commands.
(parted) p
Model: Linux device-mapper (multipath) (dm)
Disk /dev/mapper/3600c0ff00012824b04af7a5201000000: 2398GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number Start End Size Type File system Flags
1 1049kB 1081GB 1081GB primary lvm, type=8e
2 1081GB 1593GB 512GB primary lvm, type=8e
3 1593GB 1914GB 321GB primary lvm, type=8e

(parted) unit s
(parted) p
Model: Linux device-mapper (multipath) (dm)
Disk /dev/mapper/3600c0ff00012824b04af7a5201000000: 4683674624s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number Start End Size Type File system Flags
1 2048s 2111327999s 2111325952s primary lvm, type=8e
2 2111328256s 3111327999s 999999744s primary lvm, type=8e
3 3111329792s 3738281087s 626951296s primary lvm, type=8e[/CODE]
When i understand it correctly, GPT needs 34 sectors. In the beginning of the disk i have 2048 sectors free, so this
should be no proplem. I just extended the disk, so also at the end there should be enough free sectors for the
secondary GPT. I have gdisk. Is that the respective tool ?
Does anyone have experiences in converting, some “best practise” ?
Of course i will copy the first sector and also the first 2048 sectors (You never know) with dd before.

Bernd

2

Hi
I’m assuming your booting off a different disk? I have zero experience, but see this link;
https://superuser.com/questions/1250895/converting-between-gpt-and-mbr-hard-drive-without-losing-data

3

Hi,

i did with gdisk, it was very simple and went like a charm.
It was a non-boot disk.

Bernd

4

[QUOTE=berndgsflinux;58259]Hi,

i did with gdisk, it was very simple and went like a charm.
It was a non-boot disk.

Bernd[/QUOTE]
Hi
Care to share what you did?

5

I just started gdisk with the respective disk as a parameter. It recognizes automatically that the disk has a DOS MBR and proposed to convert it to GPT. I just need to write the GPT with “w”.
That’s it. I made a copy of the MBR before with “dd if=/respective/disk of=backup.file bs=512 count=1”, and also of the first 2048 sectors with
“dd if=/respective/disk of=backup_first_2048_sectors.dd bs=1048576 count=1”.

Bernd