After changing a disk partition table, Linux may not immediately notice the new layout. A reboot is the cleanest option, but on some systems you can ask the kernel to re-read the partition table.
Check current block devices
lsblk
cat /proc/partitionsAsk the kernel to re-read partitions
sudo partprobe /dev/sdXReplace /dev/sdX with the whole disk, not a partition. For example, use /dev/sda, not /dev/sda1.
When it may not work
If partitions are mounted or in use, the kernel may refuse to re-read the table. In that case, schedule a reboot during a safe maintenance window.
Always confirm the disk name before running partition-related commands.