# blockdev > Manage, query, and manipulate block devices. > More information: . - Print a report for all devices: `sudo blockdev --report` - Print a report for a specific device: `sudo blockdev --report {{/dev/sdXY}}` - Get the size of a device in 512-byte sectors: `sudo blockdev --getsz {{/dev/sdXY}}` - Set read-only: `sudo blockdev --setro {{/dev/sdXY}}` - Set read-write: `sudo blockdev --setrw {{/dev/sdXY}}` - Flush buffers: `sudo blockdev --flushbufs {{/dev/sdXY}}` - Get the physical block size: `sudo blockdev --getpbsz {{/dev/sdXY}}` - Set the read-ahead value to 128 sectors: `sudo blockdev --setra 128 {{/dev/sdXY}}`