# phpman > man > BLKDISCARD(8)

[BLKDISCARD(8)](https://www.chedong.com/phpMan.php/man/BLKDISCARD/8/markdown)                           System Administration                          [BLKDISCARD(8)](https://www.chedong.com/phpMan.php/man/BLKDISCARD/8/markdown)



## NAME
       blkdiscard - discard sectors on a device

## SYNOPSIS
       **blkdiscard** [options] [**-o** _offset_] [**-l** _length_] _device_

## DESCRIPTION
       **blkdiscard** is used to discard device sectors. This is useful for solid-state drivers (SSDs)
       and thinly-provisioned storage. Unlike [**fstrim**(8)](https://www.chedong.com/phpMan.php/man/fstrim/8/markdown), 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 explained below.

       The _device_ argument is the pathname of the block device.

### WARNING: All data in the discarded region on the device will be lost!

## OPTIONS
       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 and YB.

### -f --force
           Disable all checking. Since v2.36 the block device is open in exclusive mode (O_EXCL) by
           default to avoid collision with mounted filesystem or another kernel subsystem. The
           **--force** option disables the exclusive access mode.

### -o --offset
           Byte offset into the device from which to start discarding. The provided value must be
           aligned to the device sector size. The default value is zero.

### -l --length
           The number of bytes to discard (counting from the starting point). The provided value
           must 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. The default value extends
           to the end of the device.

### -p --step
           The number of bytes to discard within one iteration. The default is to discard all by one
           ioctl call.

### -s --secure
           Perform a secure discard. A secure discard is the same as a regular discard except that
           all copies of the discarded blocks that were possibly created by garbage collection must
           also be erased. This requires support from the device.

### -z --zeroout
           Zero-fill rather than discard.

### -v --verbose
           Display the aligned values of _offset_ and _length_. If the **--step** option is specified, it
           prints the discard progress every second.

### -V --version
           Display version information and exit.

### -h --help
           Display help text and exit.

## AUTHORS
       Lukas Czerner <<lczerner@redhat.com>>

## SEE ALSO
       [**fstrim**(8)](https://www.chedong.com/phpMan.php/man/fstrim/8/markdown)

## REPORTING BUGS
       For bug reports, use the issue tracker at <https://github.com/karelzak/util-linux/issues>.

## AVAILABILITY
       The **blkdiscard** command is part of the util-linux package which can be downloaded from Linux
       Kernel Archive <<https://www.kernel.org/pub/linux/utils/util-linux/>>.



util-linux 2.37.2                            2021-06-02                                [BLKDISCARD(8)](https://www.chedong.com/phpMan.php/man/BLKDISCARD/8/markdown)