How To View Partition Start And End Sectors With Parted

By default, parted displays partition boundaries in bytes. To view start and end positions in sectors instead, you need to set the unit explicitly using the unit command.

Using the unit command

The unit subcommand in parted sets the display unit for locations and sizes. The syntax is straightforward:

parted /dev/sda unit s print

The available units are:

s — sectors
B — bytes
kB, MB, GB, TB — decimal units
KiB, MiB, GiB, TiB — binary units
% — percentage of device size
cyl — cylinders
chs — cylinders, heads, sectors
compact — megabytes for input, human-friendly output

Example: viewing sectors

parted /dev/sda unit s print

Output:

Model: ATA ST2000DM001-1CH1 (scsi)
Disk /dev/sda: 3907029168s
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags: 

Number  Start        End          Size         File system  Name  Flags
 1      4096s        1229064191s  1229060096s               data
 2      1229064192s  3907029134s  2677964943s

Here, partition 1 starts at sector 4096 and ends at sector 1229064191.

Using the interactive shell

You can also enter parted’s interactive mode and change units there:

parted /dev/sda
(parted) unit s
(parted) print

This is useful when you need to run multiple commands against the same disk.

Converting sectors to bytes

If you need to calculate byte offsets from sector numbers, multiply by the sector size. In the example above, the sector size is 512B:

Start byte: 4096 × 512 = 2,097,152 bytes
End byte: 1,229,064,191 × 512 = 629,024,865,792 bytes

Practical considerations

When partitioning or resizing disks, working with sectors is often more precise than dealing with megabytes or gigabytes. Modern alignment best practices recommend:

Start partitions at 4096-sector (2MB) boundaries for optimal performance with 4K-native storage
Use parted -a optimal during creation to have parted handle alignment automatically

For scripting or automation, you can parse parted output using --script mode:

parted --script /dev/sda unit s print | grep -E "^\s*[0-9]+" | awk '{print $1, $2, $3}'

This extracts partition numbers, start sectors, and end sectors from the output.

Modern alternatives

While parted remains widely used, fdisk also supports sector display:

fdisk -l /dev/sda

Output from fdisk already defaults to sectors and is often faster for simple queries. For programmatic access to partition information, consider reading /proc/partitions or using lsblk with JSON output:

lsblk --json /dev/sda

Additional Tips and Best Practices

When implementing the techniques described in this article, consider these best practices for production environments. Always test changes in a non-production environment first. Document your configuration changes so team members can understand what was modified and why.

Keep your system updated regularly to benefit from security patches and bug fixes. Use package managers rather than manual installations when possible, as they handle dependencies and updates automatically. For critical systems, maintain backups before making any significant changes.

Quick Verification

After applying the changes described above, verify that everything works as expected. Run the relevant commands to confirm the new configuration is active. Check system logs for any errors or warnings that might indicate problems. If something does not work as expected, review the steps carefully and consult the official documentation for your specific version.

How to View Partition Start and End Sectors with Parted