Create partition with exact size not to specific distance

Question

How does one create a partition of exact size not to specific distance?

I have tried:

parted -a optimal /dev/sdd mkpart primary 0% 0%+1GB
# and...
parted -a optimal /dev/sdd mkpart primary 0% +1GB

To no avail.

How do I make it accept size instead of end distance?

What error messages do you get? Does `parted -a optimal /dev/sdd mkpart primary 0GB 10GB` work? — terdon, Sep 11 '13 at 12:03
This would be so much easier for me to write my script if it existed :( — Sridhar Sarnobat, Oct 15 '22 at 05:23

frostschutz · Accepted Answer · 2013-09-11T12:12:37.957

I think parted only accepts absolutes, not x+y.

You could do it like this: (+ interpreted by shell)

# start=1
# size=512
# parted /dev/loop0 unit mib mkpart primary $start $(($start+$size))
# parted /dev/loop0 unit mib print free
Model: Loopback device (loopback)
Disk /dev/loop0: 1000MiB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start    End      Size     File system  Name     Flags
        0.02MiB  1.00MiB  0.98MiB  Free Space
 1      1.00MiB  513MiB   512MiB                primary
        513MiB   1000MiB  487MiB   Free Space

...and if you want to append more, then

# start=$(($start+$size+1))
# size=128
# parted /dev/loop0 unit mib mkpart primary $start $(($start+$size))
# parted /dev/loop0 unit mib print free                           
Model: Loopback device (loopback)
Disk /dev/loop0: 1000MiB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start    End      Size     File system  Name     Flags
        0.02MiB  1.00MiB  0.98MiB  Free Space
 1      1.00MiB  513MiB   512MiB                primary
        513MiB   514MiB   1.00MiB  Free Space
 2      514MiB   642MiB   128MiB                primary
        642MiB   1000MiB  358MiB   Free Space

The +1 is entirely optional, I just like leaving 1MiB free "bumpers" between partitions, for some reason.

If you want to deal with percentages, you can obtain the device size from the shell also, using blockdev --getsize64 /dev/device, so you can move all the math out of parted into a shell script. I do this to guarantee MiB-aligned partitions, as I'm never too sure about what parted means exactly by -a optimal.

Create partition with exact size not to specific distance

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