Linux manual pages Section 8  

Name

blockdev — call block device ioctls from the command line

Synopsis

blockdev [−q] [−v] command [ command... ] device [ device... ]

blockdev −−report [ device... ]

DESCRIPTION

The utility blockdev allows one to call block device ioctls from the command line.

OPTIONS

−V

Print version and exit.

−q

Be quiet.

−v

Be verbose.

−−report

Print a report for the specified device. It is possible to give multiple devices. If none is given, all devices which appear in /proc/partitions are shown. Note that the partition StartSec is in 512-byte sectors.

COMMANDS

It is possible to give multiple devices and multiple commands.

−−flushbufs

Flush buffers.

−−getalignoff

Get alignment offset.

−−getbsz

Print blocksize in bytes.

−−getdiscardzeroes

Get discard zeroes support status.

−−getfra

Get filesystem readahead in 512-byte sectors.

−−getiomin

Get minimum I/O size.

−−getioopt

Get optimal I/O size.

−−getmaxsect

Get max sectors per request

−−getpbsz

Get physical block (sector) size.

−−getra

Print readahead (in 512-byte sectors).

−−getro

Get read-only. Print 1 if the device is read-only, 0 otherwise.

−−getsize64

Print device size in bytes.

−−getsize

Print device size (32-bit!) in sectors. Deprecated in favor of the --getsz option.

−−getss

Print sectorsize in bytes - usually 512.

−−getsz

Get size in 512-byte sectors.

−−rereadpt

Reread partition table

−−setbsz bytes

Set blocksize.

−−setfra sectors

Set filesystem readahead (same like --setra on 2.6 kernels).

−−setra sectors

Set readahead (in 512-byte sectors).

−−setro

Set read-only.

−−setrw

Set read-write.

AUTHOR

blockdev was written by Andries E. Brouwer and rewritten by Karel Zak.

AVAILABILITY

The blockdev command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.


  Copyright 1998 Andries E. Brouwer (aebcwi.nl)
Copyright 2007 Karel Zak <kzakredhat.com>

May be distributed under the GNU General Public License