TRIM(8)

NAME
trim - erase device blocks that have no needed contents

SYNOPSIS
trim [-Nfqv] [-[lo] offset [K|k|M|m|G|g|T|t|P|p|E|e]] [-r rfile] device ...

DESCRIPTION
The trim utility erases specified region of the device. It is mostly relevant for a storage that implements trim (like flash based, or thinly provisioned storage). All erased data is lost.

The trim utility should not be used upon mounted file system or active devices being a part of imported ZFS pool or other software RAID, and the kernel does not permit such usage generally. If used upon not mounted file system or inactive device, the trim utility erases blocks non-selectively, whether a block is occupied or not. Refer to the fsck_ffs(8) command having a flag -E to trim free blocks inside populated UFS, and to the zpool-trim(8) command to trim existing ZFS pool.

The following options are available:

-N  Do not actually erase anything but show what it would do (dry run). Implies -v. This is the default. Overrides -f.

-f  Perform the operation. Overrides -N.

-l  offset [K|k|M|m|G|g|T|t|P|p|E|e]

-o  offset [K|k|M|m|G|g|T|t|P|p|E|e] Specify the length -l of the region to trim or its offset -o from the beginning of the device. The whole device is erased by default unless one or both of these options are presented.

    The argument may be suffixed with one of K, M, G, T, P or E (either upper or lower case) to indicate a multiple of Kilobytes, Megabytes, Gigabytes, Terabytes, Petabytes or Exabytes, respectively.

-q  Do not output anything except of possible error messages (quiet mode). Overrides -v.

-r rfile
    Uses the length of given rfile as length of the region to erase. The whole device is erased by default.

-v  Show offset and length of actual region being erased, in bytes.

Later options override previous ones.

Note that actual success of the operation depends of underlying device driver such as ada(4), da(4) and others. Refer to corresponding manual pages for detail on possible caveats in low level support for ATA TRIM or SCSI UNMAP commands.

EXIT STATUS
If the final erase operation fails for an argument, the trim utility returns exit code 1. It can also return one of the exit codes defined in sysexits(3), as follows:

EX_USAGE
    The specified offset or length of the region is incorrect.

EX_OSERR
    There is no enough memory to proceed.

EX_NOINPUT
    The specified rfile cannot be opened (perhaps, it does not exist).

EX_IOERR
    The specified rfile cannot be examined for its size due to some system input/output error.

EX_DATAERR
    The specified rfile is not regular file, directory nor special device, so its size cannot be examined.

EX_UNAVAILABLE
    The specified rfile is special device file not supporting DIOCGMEDIASIZE ioctl(2) (probably not a disk), so its size cannot be examined.

SEE ALSO
ioctl(2), sysexits(3), ada(4), da(4), nda(4), fsck_ffs(8), zpool-trim(8)

HISTORY
The trim utility first appeared in FreeBSD 12.1.

AUTHORS
The trim utility was written by Eugene Grosbein <eugen@FreeBSD.org>.