Final test: Storage

Read the output

The vdb disk shows up in lsblk, yet it is missing from the df -h output. Why?

$ lsblk /dev/vdb
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
vdb  253:16   0  20G  0 disk
$ df -h | grep vdb
$

• A df without sudo does not see every disk.
• B The disk is not attached to the machine.
• C df does not show disks without a label.
• D df shows only mounted filesystems, and vdb has none.