What will happen after a reboot if the disk was mounted using the mount command?

After rebooting, the system will not automatically mount the disk mounted with the mount command. This is a temporary action. To have the disk mounted automatically at system startup, you need to add the appropriate entry to the /etc/fstab file.

Example entry in /etc/fstab:

# Specify device, mount point, filesystem type, and options
/dev/sdb1  /mnt/mydisk  ext4  defaults  0  2

• /dev/sdb1: Device or disk partition.
• /mnt/mydisk: Mount point. The directory must exist.
• ext4: Filesystem type.
• defaults: Default mount options (rw, suid, dev, exec, auto, nouser, async).
• 0: Indicates that the filesystem does not need to be dumped (backup). 1 or 2 indicate that it does.
• 2: Order of filesystem check at boot. 0 - do not check, 1 - check root filesystem, 2 - check other filesystems.

Check /etc/fstab configuration without reboot:

sudo mount -a

This command attempts to mount all filesystems listed in /etc/fstab that are not yet mounted. It helps identify errors in the file before rebooting.