BLKDISCARD(8) System Administration BLKDISCARD(8)NAMEblkdiscard - discard sectors on a device
SYNOPSISblkdiscard [-o offset] [-l length] [-s] [-v] device
DESCRIPTIONblkdiscard is used to discard device sectors. This is useful for
solid-state drivers (SSDs) and thinly-provisioned storage. Unlike
fstrim(8) this command is used directly on the block device.
By default, blkdiscard will discard all blocks on the device. Options
may be used to modify this behavior based on range or size, as
The device argument is the pathname of the block device.
WARNING: All data in the discarded region on the device will be lost!
The offset and length arguments may be followed by the multiplicative
suffixes KiB=1024, MiB=1024*1024, and so on for GiB, TiB, PiB, EiB, ZiB
and YiB (the "iB" is optional, e.g., "K" has the same meaning as "KiB")
or the suffixes KB=1000, MB=1000*1000, and so on for GB, TB, PB, EB, ZB
Display help text and exit.
-o, --offset offset
Byte offset in the device from which to discard. Provided value
will be aligned to the device sector size. Default value is
-l, --length length
Number of bytes after starting point to discard. Provided value
will be aligned to the device sector size. If the specified
value extends past the end of the device, blkdiscard will stop
at the device size boundary. Default value extends to the end
of the device.
Perform secure discard. Secure discard is the same as regular
discard except all copies of the discarded blocks possibly cre‐
ated by garbage collection must also be erased. It has to be
supported by the device.
Print aligned offset and length arguments.
Lukas Czerner ⟨firstname.lastname@example.org⟩
The blkdiscard command is part of the util-linux package and is avail‐
able Linux Kernel Archive ⟨ftp://ftp.kernel.org/pub/linux/utils/util-
util-linux October 2012 BLKDISCARD(8)