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+.\" -*- nroff -*-
+.TH BLKDISCARD 8 "September 2012" "util-linux" "System Administration"
+.SH NAME
+blkdiscard \- discard sectors on a device
+.SH SYNOPSIS
+.B blkdiscard
+.RB [ \-o
+.IR offset ]
+.RB [ \-l
+.IR length ]
+.RB [ \-s ]
+.RB [ \-v ]
+.I device
+
+.SH DESCRIPTION
+.B blkdiscard
+is used to discard device sectors. This is useful for solid-state
+drivers (SSDs) and thinly-provisioned storage. Unlike
+.BR fstrim (8)
+this command is used directly on the block device.
+.PP
+By default,
+.B blkdiscard
+will discard all blocks on the device. Options may be used to
+modify this behavior based on range or size, as explained below.
+.PP
+The
+.I device
+argument is the pathname of the block device.
+
+.B WARNING: All data in the discarded region on the device will be lost!
+
+.SH OPTIONS
+The \fIoffset\fR and \fIlength\fR 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, PB,
+EB, ZB and YB.
+.IP "\fB\-h, \-\-help\fP"
+Print help and exit.
+.IP "\fB\-o, \-\-offset\fP \fIoffset\fP"
+Byte offset in the device from which to discard. Provided value will be
+aligned to the device sector size. Default value is zero.
+.IP "\fB\-l, \-\-length\fP \fIlength\fP"
+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,
+.B blkdiscard
+will stop at the device size boundary. Default value extends to the end
+of the device.
+.IP "\fB\-s, \-\-secure\fP"
+Perform secure discard. Secure discard is the same as regular discard except
+all copies of the discarded blocks possibly created by garbage collection must
+also be erased. It has to be supported by the device.
+.IP "\fB\-v, \-\-verbose\fP"
+Print aligned \fIoffset\fR and \fIlength\fR arguments.
+
+.SH AUTHOR
+.nf
+Lukas Czerner <lczerner@redhat.com>
+.fi
+.SH SEE ALSO
+.BR fstrim (8)
+.SH AVAILABILITY
+The blkdiscard command is part of the util-linux package and is available
+from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.