blockdev — call block device ioctls from the command line
blockdev [−q] [−v] command [ command... ] device [
device... ]
blockdev −−report [ device... ]
−VPrint version and exit.
−qBe quiet.
−vBe verbose.
−−reportPrint 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.
−−flushbufsFlush buffers.
−−getalignoffGet alignment offset.
−−getbszPrint blocksize in bytes.
−−getdiscardzeroesGet discard zeroes support status.
−−getfraGet filesystem readahead in 512-byte sectors.
−−getiominGet minimum I/O size.
−−getiooptGet optimal I/O size.
−−getmaxsectGet max sectors per request
−−getpbszGet physical block (sector) size.
−−getraPrint readahead (in 512-byte sectors).
−−getroGet read-only. Print 1 if the device is read-only, 0 otherwise.
−−getsize64Print device size in bytes.
−−getsizePrint device size (32-bit!) in sectors. Deprecated in favor of the --getsz option.
−−getssPrint sectorsize in bytes - usually 512.
−−getszGet size in 512-byte sectors.
−−rereadptReread partition table
−−setbsz bytesSet blocksize.
−−setfra sectorsSet filesystem readahead (same like --setra on 2.6 kernels).
−−setra sectorsSet readahead (in 512-byte sectors).
−−setroSet read-only.
−−setrwSet read-write.