What is the Linux swap file used for?

• A. memory.dmp
• B. hiberfil.sys
• C. pagefile.sys
• D. swapfile

Answer: (D)

Linux swap space provides overflow memory by moving inactive pages from RAM to disk. When physical memory gets full, the kernel swaps out less-used data to the swap area so active processes can keep running, effectively extending available memory. The swap can be a dedicated partition or a swap file on the filesystem, and it can be created or resized without repartitioning. Accessing data in swap is much slower than in RAM because it relies on disk I/O, so swap helps prevent outages or thrashing but is not a substitute for sufficient RAM.

The other names are Windows-specific memory-management files (memory.dmp for crash dumps, hiberfil.sys for hibernation, pagefile.sys for paging). Linux uses swap space for virtual memory, though hibernation may use swap to store RAM contents if configured.