Questão de Linux Administration #019e3987

The mount -a command is used to mount all filesystems listed in /etc/fstab that have the auto option set. The -a flag tells mount to read /etc/fstab and mount all entries that are not explicitly marked with noauto. Filesystems with the noauto option are ignored by mount -a and must be mounted manually.

How it Works

• /etc/fstab contains entries for filesystems with mount points, options, and other parameters.
• Each entry can include the auto or noauto option in the options field (fourth column).
• mount -a processes all entries where the options field does not contain noauto. By default, if neither auto nor noauto is specified, the filesystem is considered auto.
• The command is commonly used during system boot to mount all necessary filesystems, or by an administrator after editing /etc/fstab to apply changes without rebooting.

Why the Correct Value is Right

The correct answer states that mount -a ensures all filesystems listed with the auto option in /etc/fstab are mounted. This is accurate because mount -a respects the auto/noauto option and only mounts those marked auto (or unmarked, which defaults to auto).

Why the Incorrect Values are Wrong

• The claim that mount -a mounts all filesystems with the noauto option is false; noauto explicitly excludes them from automatic mounting.
• The statement that mount -a shows all automatically mounted filesystems is incorrect; mount -a performs mounting, not listing. To view mounted filesystems, use mount without arguments or df -h.
• The idea that mount -a opens an editor with root privileges to edit /etc/fstab is wrong; that would be sudo vi /etc/fstab or similar.
• The assertion that mount -a mounts all filesystems regardless of options is false because it respects the noauto option and will skip those entries.