redhat man page for blockdev

BLOCKDEV(8)						      System Manager's Manual						       BLOCKDEV(8)

NAME
       blockdev - call block device ioctls from the command line

SYNOPSIS
       blockdev [options] commands devices

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.

COMMANDS
       --setro
	      Set read-only.

       --setrw
	      Set read-write.

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

       --getss
	      Print sectorsize in bytes - usually 512.

       --getsize
	      Print device capacity (in 512-byte sectors).

       --setra N
	      Set readahead to N 512-byte sectors.

       --getra
	      Print readahead (in 512-byte sectors).

       --flushbufs
	      Flush buffers.

       --rereadpt
	      Reread partition table.

								     May 2000							       BLOCKDEV(8)