ifup hangs during boot if there are any auto interfaces defined in /etc/network/interfaces
(including lo, but even --exclude=lo in the initscript doesn't prevent the hanging if there
are any other auto interfaces defined).

There is log output and mounting via rescue and issuing /etc/init.d/networking start does
not exhibit the problem (however I do not currently have a jessie rescue only wheezy, which
may make the difference).

Hello,

What do you mean hangs? Could you provide any more details, steps to
reproduce, output, anything?

After rebooting after an upgrade from wheezy to jessie (with no changes
to the network config), when booting the computer in to recovery mode
(because normal mode stop displaying messages and fails to boot at, at
stays stuck at one of the rcS.d scripts boot messages that still
displays in with 'quiet' enabled), the various LSB messages are
displayed until Starting 'Raise network interfaces' is displayed at
which point the LSB cutesy spinner thing (astrisks moving accross the
status area) does it's cutsey spinner thing forever (no timeout, no
succes, just stuck there for as long as  you care to wait).

If I boot with conigure interfaces set to "no" this issue doesn't occur.

If I empty /etc/network/interfaces the problem still occurs unless I
also edit /etc/init.d/networking to do ifup -a --exclude=lo $exclusions
$verbose instead of ifup -a $excludions $verbose.

if /etc/network/interfaces is not empty (or with --exclude=lo, empty
except for lo) then the problem is present.

There are no log messages that I can see.

I have confirmed the hang is on ifup not ifup_hotplug but other than
that all I can figure out so far is that ifup is hanging for no apparent
reason.

ifquery does work though, so if I empty the /etc/network/interfaces and
make ifup only occur if ifquery is non-empty then the problem doesn't
occur (because ifup doesn't run and ifup is hanging).

Regards,

Daniel

I had the same problem that I tracked down by adding --verbose to the ifup
commands.

This led to /etc/network/if-up.d/mountnfs Adding -x to the shell options
showed that the hanging command was

"mount -a -t$NETFS" which was executed as "mount -a -tcifs"

It turns out I had a filesystem mount in /etc/fstab of type cifs that
required a password and that lacked the "noauto" keyword.