The general options are not needed most of the time. They allow
for increased flexibility and security.
It is possible to protect a partition from writing. Even
the superuser won't be able to write there. This is seldom
used on a normal hard drive partition though.
- User mountable
This is generally used with the following option, and
is useful for removable media. It allows anyone to
activate the connection at any time. Normally, only root
(the superuser) can establish a mount.
- Do not mount at boot time
Especially useful for removable media, it prevents the system
from trying to establish a mount at boot time.
- No program allowed to execute
This is a security feature, which is especially useful for
removable media. If you set the
user mountable option on a
removable media, it allows any user to come and install a set of
files, specifically setup, to give him full access to your
system (administrator privileges). This option would prevent
this situation from occurring.
- No special device file support
This is a security feature.
Special devices are generally created with proper access rights
in the /dev directory. They may be created in other places too,
with the mknod command. This feature prevents mounting
media with special devices created with relaxed security. Such
devices would defeat all security on the system.
- No setuid programs allowed
This is yet another security feature. It is a compromise between
full access and the above option (no execution allowed).
If you set this option, the system will deny privileged
programs their special rights. A privileged program
is one that switches the user to another identity while
it is running (generally root). This allows the user
to do special tasks that only the supervisor can do.
- User quota enabled
This flag tells the kernel to enable quota accounting on the
filesystem. Quota accounting maintains, for each user in real
time, the amount of disk space used and the amount of files
and directories they own. Limits may be imposed on some or
This is controlled separately for each file system. The
file quota.user is created in the root of the
filesystem (linuxconf will create it for you if you activate
this feature). The utility
quotacheck is run to initialize the file with the current state
of the filesystem. The kernel, from now on, will silently update
this for each user account.
This is useful for preventing a single user from filling the disk.
- Group quota enabled
This is the same feature as user quota enabled, but
for groups. The group quotas
hold the sum of the quotas of all file members of the group. A
file quota.group is created when this feature is enabled and
the utility quotacheck is used to initialize the file.
While a user may be under his personal quota limit, the quota
of his group may be over its limit. The user will be prevented
from creating new files and/or growing them.