Which command informs the OS of partition table changes?

• A. partprobe
• B. partx
• C. kpartx
• D. partprobe -s

Answer: (A)

When you change a partition table, the kernel’s view of the disk doesn’t automatically update. The command that asks the OS to re-read the partition tables and refresh its partition information is partprobe. It probes the block devices and informs the kernel about the new or changed partitions so they become visible as devices you can mount and use again without rebooting. This is the standard, general-purpose way to propagate partition-table changes into the running system.

The other tools have different roles. partx can also update the kernel’s partition information but is older and depends on more explicit invocation for specific devices. kpartx is used to create device mappings for partitions (often with complex setups or loop devices), not simply to inform the kernel of changes. Using partprobe with the -s option adds a summary display, but the essential action—re-reading the partition table—remains partprobe.