blockdev(8) - Linux man page

Name

blockdev - call block device ioctls from the command line

blockdev [options] commands devices
blockdev --report [devices]

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.
--report: Print a report for devices. Note that the partition StartSec is in 512-byte sectors.

--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.
--getbsz: Print blocksize in bytes.
--setbsz N: Set blocksize to N bytes.
--getsize: Print device size in sectors (BLKGETSIZE). Deprecated in favor of the --getsz option.
--getsize64: Print device size in bytes (BLKGETSIZE64)
--getsz: Get size in 512-byte sectors (BLKGETSIZE64 / 512).
--setra N: Set readahead to N 512-byte sectors.
--getra: Print readahead (in 512-byte sectors).
--setfra N: Set filesystem readahead (same like --setra on 2.6 kernels).
--getfra: Get filesystem readahead.
--flushbufs: Flush buffers.
--rereadpt: Reread partition table.

blockdev was written by Andries E. Brouwer.

The blockdev command is part of the util-linux-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.

guestfish(1), guestfs(3), mount(8)