blockdev

Calling the block device control program from the command line

Supplementary instructions

blockdev command Call the "ioxtls" function in the command to control the device.

grammar

blockdev(options)(parameters)

Options

-V: Print version number and exit;
-q: Quiet mode;
-v: detailed information mode;
--setro: read-only;
--setrw: write only;
--getro: Print read-only status, "1" means read-only, "0" means non-read-only;
--getss: Print sector size. Usually 521;
--flushbufs: Flush buffer;
--rereadpt: Reread the partition table.

Parameters

Device file name: Specify the device file name of the disk to be operated.

Example

Set the device as read-only:

blockdev --setro /dev/hda4

Read whether the device is read-only:

blockdev --getro /dev/hda4

Set the identifier to be readable and writable:

blockdev --setrw /dev/hda4