tldr/pages/linux/fallocate.md

fallocate

Reserve or deallocate disk space to files. The utility allocates space without zeroing. More information: https://manned.org/fallocate.

• Reserve a file taking up 700 MiB of disk space:

fallocate {{[-l|--length]}} {{700M}} {{path/to/file}}

• Shrink an already allocated file by 200 MiB:

fallocate {{[-c|--collapse-range]}} {{[-l|--length]}} {{200M}} {{path/to/file}}

• Shrink 20 MB of space after 100 MiB in a file:

fallocate {{[-c|--collapse-range]}} {{[-o|--offset]}} {{100M}} {{[-l|--length]}} {{20M}} {{path/to/file}}