Update cheatsheets

tldr/linux/blockdev

@@ -0,0 +1,41 @@
+---
+syntax: markdown
+tags: [tldr, linux]
+source: https://github.com/tldr-pages/tldr.git
+---
+# blockdev
+
+> Manage, query, and manipulate block devices.
+> More information: <https://manned.org/blockdev>.
+
+- 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}}`