disk-utils/blockdev.8

   1 .\" -*- nroff -*-
   2 .\" Copyright 1998 Andries E. Brouwer (aeb@cwi.nl)
   3 .\" Copyright 2007 Karel Zak <kzak@redhat.com>
   4 .\"
   5 .\" May be distributed under the GNU General Public License
   6 .TH BLOCKDEV 8 "Aug 2010" ""
   7 .SH NAME
   8 blockdev \- call block device ioctls from the command line
   9 .SH SYNOPSIS
  10 .B blockdev
  11 .RB [ \-q ]
  12 .RB [ \-v ]
  13 .IR command
  14 .RI [ command ...]
  15 .IR device
  16 .RI [ device ...]
  17 .br
  18 .B blockdev
  19 .B \-\-report
  20 .RI [ device ...]
  21 .SH DESCRIPTION
  22 The utility
  23 .B blockdev
  24 allows one to call block device ioctls from the command line.
  25 .SH OPTIONS
  26 .IP "\fB\-V\fP"
  27 Print version and exit.
  28 .IP "\fB\-q\fP"
  29 Be quiet.
  30 .IP "\fB\-v\fP"
  31 Be verbose.
  32 .IP "\fB\-\-report\fP"
  33 Print a report for the specified device. It is possible to give multiple
  34 devices. If none is given, all devices which appear in /proc/partitions are
  35 shown. Note that the partition StartSec is in 512-byte sectors.
  36 .SH COMMANDS
  37 It is possible to give multiple devices and multiple commands.
  38 .IP "\fB\-\-flushbufs\fP"
  39 Flush buffers.
  40 .IP "\fB\-\-getalignoff\fP"
  41 Get alignment offset.
  42 .IP "\fB\-\-getbsz\fP"
  43 Print blocksize in bytes.
  44 .IP "\fB\-\-getdiscardzeroes\fP"
  45 Get discard zeroes support status.
  46 .IP "\fB\-\-getfra\fP"
  47 Get filesystem readahead in 512-byte sectors.
  48 .IP "\fB\-\-getiomin\fP"
  49 Get minimum I/O size.
  50 .IP "\fB\-\-getioopt\fP"
  51 Get optimal I/O size.
  52 .IP "\fB\-\-getmaxsect\fP"
  53 Get max sectors per request
  54 .IP "\fB\-\-getpbsz\fP"
  55 Get physical block (sector) size.
  56 .IP "\fB\-\-getra\fP"
  57 Print readahead (in 512-byte sectors).
  58 .IP "\fB\-\-getro\fP"
  59 Get read-only. Print 1 if the device is read-only, 0 otherwise.
  60 .IP "\fB\-\-getsize64\fP"
  61 Print device size in bytes.
  62 .IP "\fB\-\-getsize\fP"
  63 Print device size (32-bit!) in sectors. Deprecated in favor of the --getsz option.
  64 .IP "\fB\-\-getss\fP"
  65 Print sectorsize in bytes - usually 512.
  66 .IP "\fB\-\-getsz\fP"
  67 Get size in 512-byte sectors.
  68 .IP "\fB\-\-rereadpt\fP"
  69 Seread partition table
  70 .IP "\fB\-\-setbsz\fP \fIbytes\fP"
  71 Set blocksize.
  72 .IP "\fB\-\-setfra\fP \fIsectors\fP"
  73 Set filesystem readahead (same like --setra on 2.6 kernels).
  74 .IP "\fB\-\-setra\fP \fIsectors\fP"
  75 Set readahead (in 512-byte sectors).
  76 .IP "\fB\-\-setro\fP"
  77 Set read-only.
  78 .IP "\fB\-\-setrw\fP"
  79 Set read-write.
  80 .SH AUTHOR
  81 blockdev was written by Andries E. Brouwer and rewritten by Karel Zak.
  82 .SH AVAILABILITY
  83 The blockdev command is part of the util-linux-ng package and is available from
  84 ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
  85