I’m adding a disk to an ubuntu machine and creating a new partition which uses the whole disk.

GNU Parted 2.2
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Error: /dev/sdb: unrecognised disk label

So I make a new dos partition

(parted) mklabel
New disk label type? msdos
(parted) print
Model: - (scsi)
Disk /dev/sdb: 53.7GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start  End  Size  Type  File system  Flags

(parted) mkpart primary ext4 0 -1
Warning: The resulting partition is not properly aligned for best performance.

You should align the first partition at block 64
(parted) mkpart primary ext4 64 -1
mkpart syntax is: mkpartfs part-type fs-type start-mb end-mb
so this just wastes the first 64 MB of space on the disk. Setting the start at 1 avoids the error message as well.

mkpart primary ext4 1 -1

And your error free. Go forth and partition.
Thanks to Stefan.
This is why I put stuff on the internet.



14 responses to “Warning: The resulting partition is not properly aligned for best performance.”

  1. NoOneElse Avatar

    Hm, that just wastes the first 64MB of your device. Though not optimal either, a

    (parted) mkpart primary ext4 1 -1

    at least only wastes 1MB.

    1. derak Avatar

      I see what you mean.
      Thanks for the feedback.

  2. jaes Avatar

    Just a post to say thanks cause this post got me out of serious chronic headaches :)

  3. z Avatar

    Thanks for the info on how you guys used Parted. There is lacking documentation on how to properly format these Advance Format drives that lie to the OS.

    parted -a optimal /dev/sdb

    (parted) u s

    (parted) mkpart primary linux-swap 1 1G

    (parted) mkpart primart ext4 1953792s -1

    (parted) p
    Model: ATA WDC WD10EARS-00Y (scsi)
    Disk /dev/sdb: 1953525168s
    Sector size (logical/physical): 512B/512B
    Partition Table: msdos

    Number Start End Size Type File system Flags
    1 2048s 1953791s 1951744s primary linux-swap(v1)
    2 1953792s 1953525167s 1951571376s primary ext4

    This seemed to solve all of my performance problems.

  4. […] this excellent post on how to format a drive larger than 2TB. Supporting information was taken from this blog post with regard to how the drive alignment works. Finally this article from IBM was a good read on […]

  5. Dmitry Sherman Avatar

    thanks that helped me partition my 2TB hard drive.
    for some reason the debian squeeze’s fdisk does support GPT partitions but after creation i didnt see it in /dev/sdb1. only saw /dev/sdb

    after using parted the problem solved.

  6. Loren Copeland Avatar

    You can change the units to sectors by typing “unit s” while in parted.

    1. derak Avatar

      Thanks for the tip.

  7. Beerman Avatar

    Thanks, man. I hate when I´m confronted with warnings, and your tip helped me solve it with no problems.

  8. sam Avatar

    Percents work as well and get auto aligned.
    (parted) mkpart
    Partition name? []? data
    File system type? [ext2]? ext4
    Start? 0%
    End? 100%

    1. derak Avatar

      Thanks for the tip Sam. Didn’t know it would accept percents.

    2. Nick Avatar

      Awsome tip. Easiest way to partition a 2TB+ drive; sure wish the help would mention this.

      1. Wind Avatar

        Holy Todeol, so glad I clicked on this site first!

  9. dragon788 Avatar

    Thanks guys, the percents tip is the one that fixed it for me. Was trying to create a partition to fill a disk on a VM and no combination of sectors seemed to be working, and even defining a "correct" start of a divisible by 8 sector and 100% was failing.

Verified by MonsterInsights