Provided by: util-linux_2.27.1-6ubuntu2_i386 bug

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. 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.

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/.