Welcome to little lamb

Code » anopa » jjk » tree

[jjk] / doc / aa-terminate.pod

=head1 NAME

aa-teminate - Tries to close/unmount everything it can

=head1 SYNOPSIS

B<aa-terminate> [B<-D>] [B<-O> I<FILE|FD>] [B<-l>] [B<-a>] [B<-q> | B<-v>]

=head1 OPTIONS

=over

=item B<-a, --apis>

When done, unmount API file systems: I</run>, I</sys>, I</proc> and I</dev> If a
regular umount call fails, a lazy umount will be performed.

=item B<-D, --double-output>

Enable double-output mode. Instead of using stdout for regular output, and
stderr for warnings and errors, everything is sent both to stdout and stderr.
This is intended to redirect stderr to a log file, so full output can be both
shown on console and logged.

B<Deprecation warning:> Note that this option has been deprecated and will be
removed in the next version; You should use B<--log-file> instead.

=item B<-h, --help>

Show help screen and exit.

=item B<-l, --lazy-umounts>

When nothing can be done anymore (see L<B<DESCRIPTION>|/DESCRIPTION> below) and
there are still active mount points, run the loop again performing lazy
unmounts: making the mount point unavailable for new accesses, and actually
performing the unmount when the mount point ceases to be busy.

=item B<-O, --log-file> I<FILE|FD>

Will duplicate all output (everything written to stdout or stderr) to the given
file or file descriptor. I<FILE|FD> can either be a (previously opened for
writing) file descriptor (must be > 2), or a file which will then be opened in
append mode.

=item B<-q, --quiet>

Do not output anything (not even warnings of "left overs" when done; See
B<--verbose> for more).

=item B<-V, --version>

Show version information and exit.

=item B<-v, --verbose>

Out information about everything that is tried. By default it only outputs when
something succeeds (and warnings of "left-overs" when done, listing anything
that couldn't be closed/removed/unmounted).
With this option, B<aa-terminate>(1) will output about any operation it
attempts, as well as an error message on failure. This is usually not important
information and mostly useful for testing/debugging purposes.

=back

=head1 DESCRIPTION

Ideally, when shutting down/rebooting the system, anything that was
opened/mounted on boot (i.e. via B<aa-start>(1) during stage 0/1) should be
closed/unmounted automatically (i.e. via B<aa-stop>(1) during stage 3/4), as
defined on the relevant services.

However, things might not go as planned, for one reason or another (starting
with, things might have been opened/mounted outside of any services).

B<aa-terminate>(1) is aimed at closing/unmounting all that can be done at the
end of e.g. stage 3/4, right before powering off/rebooting.

To do so, it will try to:

=over

=item 1. Turn all swaps off

=item 2. Unmount everything but I</>, I</dev>, I</proc>, I</sys> and I</run>

=item 3. Close all loop devices (I</dev/loop*>)

=item 4. Remove all DM block devices (I</dev/dm-*>)

=back

When done, if there are still things to do (i.e. certain operations failed) and
at least one attempt was successful, it will try it all again, until either
there's nothing left to do, or it can't do anything else.

If option B<--lazy-umounts> was specified and there are still active mount
points, it will try all over again, performing lazy umounts.

Then, if option B<--apis> was specified it will umount API file systems:
I</run>, I</sys>, I</proc> and I</dev> If a regular umount call fails, a lazy
umount will be performed (regardless of whether option B<--lazy-umounts> was
used or not).

Finally, unless option B<--quiet> was specified, warnings will be emitted for
everything left (swaps, mount points, loop/block devices that couldn't be
closed/unmounted/removed), if there is any.

=head1 NOTE

B<aa-terminate>(1) requires I</dev> and I</proc> to be mounted. Specifically, it
reads I</proc/swaps> to list active swaps and I</proc/mounts> for mount points;
It also reads I</dev> for loop/block devices, and uses I</dev/mapper/control> to
remove block devices.

=head1 RETURN CODES

Return codes are somewhat unified inside B<anopa>. Odd return codes represent
fatal errors, and are detailed in B<anopa-rc>(1)

Possible even return codes for B<aa-terminate>(1) are a bitwise combination of
the following flags:

=over

=item B<2>

At least 1 swap was left over

=item B<4>

At least 1 mount was left over

=item B<8>

At least 1 loop device was left over

=item B<16>

At least 1 DM block device was left over

=back