Partitioning with cfdisk
cfdisk is the partitioning tool that the Salix installer runs to let you set up your partitions. On disks that use the GPT partitioning scheme, the installer runs cgdisk instead, which works mostly the same way. This page explains how disks and partitions are named and how to use each of the cfdisk commands. For a quick walkthrough of partitioning during installation, see the Salix Startup Guide.
Hard disk and partition names
Hard disk names
SCSI harddisks are named with sdx, where x is a harddisk letter. The disk with the lowest SCSI ID on the first controller will become sda, the next after that, sdb, and so on.
Not all disks follow this scheme, though:
- NVMe drives are named nvmeXnY, where X is the number of the NVMe controller (starting from 0) and Y the number of the namespace on it (starting from 1). The first NVMe drive will usually be nvme0n1, the second nvme1n1, and so on.
- SD cards and eMMC storage, which is common on small laptops and tablets, are named mmcblkX, where X is a number starting from 0. The first one will be mmcblk0, the next mmcblk1, and so on.
Hard disk partitions
GNU/Linux systems often use a partition scheme inherited from MS-DOS. With this, a harddisk can have up to four primary partitions. If you want more, you have to make one of these an extended partition where you can make several logical partitions. The partitions are named with the disk they belong to, and a number. The first primary partition on the first disk is therefore sda1, the second primary partition is sda2, and so on. The first and second logical partition on an extended partition on the first disk is sda5 and sda6, and so on.
For NVMe drives and SD cards or eMMC storage, a p is added between the disk name and the partition number, since the disk name already ends in a number. The first partition on the first NVMe drive is therefore nvme0n1p1, and the first partition on the first SD card is mmcblk0p1.
Using cfdisk
The user interface
After cfdisk is started you’ll get an interface where the current partition table is listed with the names and some data about each partition and some command buttons on the bottom of the screen. To change between partitions, use the up and down arrow keys. To change between commands, use the left and right arrow keys.
Deleting a partition
To delete an existing partition, highlight it with the up and down keys, select the
Delete command with the left and right arrow keys and press Enter
or just press D.
Making a new partition
To make a new partition, select the New command with the left and right arrow keys, and
press Enter. You’ll get the choice between a primary and a logical partition. If you
want a logical partition, the program will automatically make an extended partition for
you. Then you must choose the size of the partition (in MB). If you can’t enter a value
in MB, return to the main screen with the Esc key and select MB with the Units command.
Set the type of a partition
To set the type of a partition, highlight
the desired partition and select the Type command. You’ll get a list of different types.
Press space, and you’ll get even more. Find what type you need, and enter the number at
the prompt. Linux is 83, Linux swap is 82.
Make a partition bootable
To be able to boot from a primary partition, you need to make it bootable. Highlight the partition and select the Bootable command.
Write the result to disk and quit
When you are content with the layout of the disk, select the Write command. The partition table will be written to disk. Remember that this will destroy all data on partitions you have deleted or changed. You should, therefore, be very sure that you want to do this before actually pressing the Return key.
To exit the program, select the Quit command. The installer will then detect any partitions you have created and offer you the option to assign mount points to them.