Jtdcftul

I am wondering what Start and End value to choose when partitioning my ext. SSD using fdisk.

fdisk suggests 2048-250069679, default 2048 but 250069679 cannot be divided by 512 nor by 2048. Wouldn't it be better to set the Start and End value to a number that can be divided by 512 or 2048 or 4096?

For example: Start 4096 and End 250068992

Command (m for help): p



Disk /dev/sda: 119,2 GiB, 128035676160 bytes, 250069680 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0xa4b57300





Command (m for help): n

Partition type

   p   primary (0 primary, 0 extended, 4 free)

   e   extended (container for logical partitions)

Select (default p): p

Partition number (1-4, default 1): 

First sector (2048-250069679, default 2048): 

Last sector, +sectors or +size{K,M,G,T,P} (2048-250069679, default 250069679): 



Created a new partition 1 of type 'Linux' and of size 119,2 GiB.





Command (m for help): p

Disk /dev/sda: 119,2 GiB, 128035676160 bytes, 250069680 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0xa4b57300



Device     Boot Start       End   Sectors   Size Id Type

/dev/sda1        2048 250069679 250067632 119,2G 83 Linux



Command (m for help): i

Selected partition 1

         Device: /dev/sda1

          Start: 2048

            End: 250069679

        Sectors: 250067632

      Cylinders: 15566

           Size: 119,2G

             Id: 83

           Type: Linux

    Start-C/H/S: 0/32/33

      End-C/H/S: 206/29/63





mkfs.ext4 /dev/sda1

mke2fs 1.43.4 (31-Jan-2017)

Ein Dateisystems mit 31258454 (4k) Blöcken und 7815168 Inodes wird erzeugt.

UUID des Dateisystems: fdce9286-4545-447c-9cca-7d67f5bb9f43

Superblock-Sicherungskopien gespeichert in den Blöcken: 

    32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 

    4096000, 7962624, 11239424, 20480000, 23887872





fdisk -l

Disk /dev/sda: 119,2 GiB, 128035676160 bytes, 250069680 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0xa4b57300



Device     Boot Start       End   Sectors   Size Id Type

/dev/sda1        2048 250069679 250067632 119,2G 83 Linux

And how can it be that the Sectors number is lower than the End value?

Command (m for help): i

Selected partition 1

         Device: /dev/sda1

          Start: 2048

            End: 250069679

        Sectors: 250067632

      Cylinders: 15566

           Size: 119,2G

             Id: 83

           Type: Linux

    Start-C/H/S: 0/32/33

      End-C/H/S: 206/29/63

Alignment doesn’t matter for the end sector. Sectors are numbered from 0; fdisk is suggesting the last sector on your disk (which has 250069680 sectors).

  Start: 2048

    End: 250069679

Sectors: 250067632

is correct, 250069679 minus 2048 plus one is 250067632: the partition contains 250067632 sectors, starting at offset 2048.