Fallocate

fallocate preallocate or deallocate space to a file, it is not supported in ZFS, use dd instead of.

• Man page: https://man7.org/linux/man-pages/man1/fallocate.1.html

Examples

fallocate -l 1G NEW_filename
fallocate -l 24M NEW_filename
-l --length

fallocate -l 1G NEW_filename
fallocate: fallocate failed: No space left on device

fallocate
fallocate: no filename specified

Options

fallocate -h

Usage:
 fallocate [options] <filename>

Preallocate space to, or deallocate space from a file.

Options:
 -c, --collapse-range remove a range from the file
 -d, --dig-holes      detect zeroes and replace with holes
 -i, --insert-range   insert a hole at range, shifting existing data
 -l, --length <num>   length for range operations, in bytes
 -n, --keep-size      maintain the apparent size of the file
 -o, --offset <num>   offset for range operations, in bytes
 -p, --punch-hole     replace a range with a hole (implies -n)
 -z, --zero-range     zero and ensure allocation of a range
 -x, --posix          use posix_fallocate(3) instead of fallocate(2)
 -v, --verbose        verbose mode

 -h, --help           display this help
 -V, --version        display version

For more details see fallocate(1).

Execution examples

fallocate
fallocate: no filename specified

fallocate -v -l 10G NEW_10G_FILE
(not output on success)

Related commands

• df
• truncate
• head
• dd if=/dev/zero of=YOUR_BIG_FILE bs=1 count=0 seek=100G
• head -c 1G </dev/urandom >myfile
• mkswap

See also

• fallocate, mkfile
• file, File system, directory, touch, mkdir, ls, ln truncate, fallocate, split, stat, inode, File descriptor, superblock, block size (blockdev), fuser, lsof, scrub, chattr, ulimit (nofiles), cp, mv, file (command), mkfifo, chmod
• Swap, swapon, swapoff, mkswap, swaplabel, free,sar -r, sar -S, sar -W, vmstat, vm.swappiness, /proc/swaps, /etc/fstab, Add a swap disk, systemd.swap
• du, du -hs, Disk space usage, df, ls, tree, find, docker system df, journalctl --disk-usage, No space left on device, ENOSPC, sar -F, growpart, resize2fs, ncdu, duf, dua-cli

https://github.com/openzfs/zfs/issues/326