partprobe

Partprobe is a Linux utility used to inform the running kernel about changes to a disk’s partition table. It is typically employed after creating, deleting, or resizing partitions so that the system recognizes the new layout without requiring a reboot. The program reads the partition table from one or more block devices and instructs the kernel to re-scan and update its in-kernel representation of the partitions.

Usage is simple and usually requires root privileges. A common invocation is to probe a specific device, for example: partprobe /dev/sda. Running it without arguments probes all suitable devices. It is often used after tools that modify partition tables, such as fdisk, sfdisk, gdisk, or parted.

Behavior and limitations: partprobe updates the kernel’s view of partitions but does not move or unmount any mounted filesystems. If a partition or device is in active use, the kernel may be unable to re-read the table cleanly, and a reboot or unmount/remount may be necessary to fully reflect changes. In some scenarios, alternative commands such as blockdev --rereadpt, or the partx/kpartx tools, may be used to achieve similar results or handle special mappings.

Implementation notes: Partprobe is commonly provided by the util-linux or related package on many Linux distributions. Its exact behavior can vary slightly between systems. It is a Linux-specific tool and is not applicable to non-Linux operating systems.

See also: blockdev --rereadpt, partx, kpartx, udev, rescan.