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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | COMMANDS | AUTHOR | AVAILABILITY | COLOPHON |
BLOCKDEV(8) System Administration BLOCKDEV(8)
blockdev - call block device ioctls from the command line
blockdev [-q] [-v] command [command...] device [device...]
blockdev --report [device...]
blockdev -h|-V
The utility blockdev allows one to call block device ioctls from the
command line.
-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.
-h, --help
Display help text and exit.
-V, --version
Print version and exit.
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 sector size in bytes – usually 512.
--getsz
Get size in 512-byte sectors.
--rereadpt
Reread partition table
--setbsz bytes
Set blocksize. Note that the block size is specific to the
current file descriptor opening the block device, so the
change of block size only persists for as long as blockdev has
the device open, and is lost once blockdev exits.
--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.
blockdev was written by Andries E. Brouwer and rewritten by Karel
Zak.
The blockdev command is part of the util-linux package and is
available from https://www.kernel.org/pub/linux/utils/util-linux/.
This page is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have a
bug report for this manual page, send it to
util-linux@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2017-07-05. If you discover any rendering problems in this HTML ver‐
sion of the page, or you believe there is a better or more up-to-date
source for the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original man‐
ual page), send a mail to man-pages@man7.org
util-linux August 2010 BLOCKDEV(8)
Pages that refer to this page: mount(8)