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


       blockdev - call block device ioctls from the command line


       blockdev [-q] [-v] command [command...] device [device...]
       blockdev --report [device...]


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


       -V     Print version and exit.

       -q     Be quiet.

       -v     Be verbose.

              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.


       It is possible to give multiple devices and multiple commands.

              Flush buffers.

              Get alignment offset.

              Print blocksize in bytes.

              Get discard zeroes support status.

              Get filesystem readahead in 512-byte sectors.

              Get minimum I/O size.

              Get optimal I/O size.

              Get max sectors per request

              Get physical block (sector) size.

              Print readahead (in 512-byte sectors).

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

              Print device size in bytes.

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

              Print sectorsize in bytes – usually 512.

              Get size in 512-byte sectors.

              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).

              Set read-only.

              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