73 lines
2.1 KiB
Groff
73 lines
2.1 KiB
Groff
.\" -*- nroff -*-
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.TH BLKDISCARD 8 "October 2012" "util-linux" "System Administration"
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.SH NAME
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blkdiscard \- discard sectors on a device
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.SH SYNOPSIS
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.B blkdiscard
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.RB [ \-o
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.IR offset ]
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.RB [ \-l
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.IR length ]
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.RB [ \-s ]
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.RB [ \-v ]
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.I device
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.SH DESCRIPTION
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.B blkdiscard
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is used to discard device sectors. This is useful for solid-state
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drivers (SSDs) and thinly-provisioned storage. Unlike
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.BR fstrim (8)
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this command is used directly on the block device.
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.PP
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By default,
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.B blkdiscard
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will discard all blocks on the device. Options may be used to modify
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this behavior based on range or size, as explained below.
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.PP
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The
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.I device
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argument is the pathname of the block device.
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.PP
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.B WARNING: All data in the discarded region on the device will be lost!
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.SH OPTIONS
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The
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.I offset
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and
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.I length
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arguments may be followed by the multiplicative suffixes KiB=1024,
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MiB=1024*1024, and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is
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optional, e.g., "K" has the same meaning as "KiB") or the suffixes
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KB=1000, MB=1000*1000, and so on for GB, PB, EB, ZB and YB.
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.IP "\fB\-h, \-\-help\fP"
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Print help and exit.
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.IP "\fB\-o, \-\-offset\fP \fIoffset\fP"
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Byte offset in the device from which to discard. Provided value will be
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aligned to the device sector size. Default value is zero.
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.IP "\fB\-l, \-\-length\fP \fIlength\fP"
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Number of bytes after starting point to discard. Provided value will be
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aligned to the device sector size. If the specified value extends past
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the end of the device,
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.B blkdiscard
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will stop at the device size boundary. Default value extends to the end
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of the device.
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.IP "\fB\-s, \-\-secure\fP"
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Perform secure discard. Secure discard is the same as regular discard
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except all copies of the discarded blocks possibly created by garbage
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collection must also be erased. It has to be supported by the device.
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.IP "\fB\-v, \-\-verbose\fP"
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Print aligned
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.I offset
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and
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.I length
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arguments.
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.SH AUTHOR
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.MT lczerner@redhat.com
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Lukas Czerner
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.ME
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.SH SEE ALSO
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.BR fstrim (8)
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.SH AVAILABILITY
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The blkdiscard command is part of the util-linux package and is available
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.UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
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Linux Kernel Archive
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.UE .
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