Linux multipath device how to partition?

Question

Linux multipath device how to partition?
Which command can realize the partition?
fdisk, kpartx and parted Which command correctly?

Answer 1

Hello.
I usually use the command "parted". Here is an example of what I do. You have to run it as ROOT of course.
Example drive: /dev/mapper/mpath_drive
Steps:
run command with the full path for the drive
print what you have, just to make sure it's not being used
IF there is not a label created, you will receive a warning telling that. Then, ceate the label for the drive making sure you are NOT using the drive or you will loose everything!
print what you have
Change the units to what's more suitable for you (maybe Megabytes)
Print the partition table once again to see the space you have available
create the partitions one by one, making sure you don't overlap them
print once you finish the partitions definition
quit
Add (if you need/want to) the partitions into /etc/fstab
bash>parted /dev/mapper/mpath_drive
(parted)print
(parted)mklabel gpt #MAKE SURE THE DISK IS NOT BEING USED OR YOU WILL REMOVE ALL THE DATA
(parted)print
(parted)unit Mb
(parted)print
          Model: Linux device-mapper (multipath) (dm)
          Disk /dev/mapper/asm_data1: 2199023MB
          Sector size (logical/physical): 512B/512B
          Partition Table: gpt
          Number  Start   End     Size   File system  Name     Flags    
     7. (parted)mkpart primary ext2 INIT_MB END_MB  #YOU WILL SET THOSE VALUES BASED ON THE AMOUNT OF SPACE YOU HAVE    
     8. (parted)print #In this example, I have created four 500gb partitions with a 2tb drive for ASM.
          Model: Linux device-mapper (multipath) (dm)
          Disk /dev/mapper/mpath_drive: 2199023MB
          Sector size (logical/physical): 512B/512B
          Partition Table: gpt
          Number  Start      End        Size      File system  Name     Flags
           1      1.00MB     549757MB   549756MB               primary
           2      549758MB   1099515MB  549757MB               primary
           3      1099516MB  1649272MB  549756MB               primary
           4      1649273MB  2199023MB  549750MB               primary
     9. (quit)
In the top of that, IF you want to be more clean, you can edit the file  /etc/multipath.conf to add pretty names to the drives. I do that to maintain control over the disks in ASM so I know what is what basically.
Hope it helps.
Thanks,
Alex.