Scroll to navigation

f2fs_io(8) System Administration Utilities f2fs_io(8)


f2fs_io - f2fs ioctl utility


f2fs_io is used to send various commands to the f2fs file system for administrative purposes.


Set the verity flags associated with the specified file.
Get the flags associated with the specified file.
Set an f2fs file on specified file. The flag can be casefold, compression, and nocompression.
Freeze and stop all IOs for the file system mounted on dir. The level parameter can be:
going down with full sync
going down with checkpoint only
going down with no sync
going down with metadata flush
going down with fsck mark
Get or set the pinning status on a file.
Request that space be allocated on a file. The keep_size parameter can be either 1 or 0.
Write a given pattern to file_path. The pattern parameter can be:
incrementing numbers
random numbers
The IO parameter can be:
buffered I/O
direct I/O
direct I/O with O_DSYNC
Read data in file_path and print print_nbytes. The IO options can be:
buffered I/O
direct I/O
get block address in file
Start, end, or run gc_urgent for a given time period
Defragment a file.
Copy file from src_path to dst_path. The pattern parameter can be:
use direct I/O
use mmap for source file
use sendfile to transfer data
Get the number of compressed blocks.
Release compressed blocks to get free space.
Reserve free blocks to prepare decompressing blocks in the file.
Trigger filesystem GC


This version of f2fs_io has been written by Jaegeuk Kim <>.


f2fs_io is available from git://

March 2020 f2fs-tools