Provided by: util-linux_2.20.1-5.1ubuntu20.9_amd64 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.

       --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  from