Subject: Re: [vserver] debian jessie error on vserver shutdown
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Mon, 9 Nov 2015 19:51:00 +0100

On Mon, Nov 09, 2015 at 10:49:15AM -0700, Daniel Urist wrote:
> I am in the process of upgrading from debian wheezy to jessie
> for both hosts and guests. All hosts and guests are running
> sysv-rc (no systemd!). I'm getting the following error on
> shutdown with jessie guests running on jessie hosts:

Hey Daniel,

>  /usr/share/util-vserver/vserver.stop: line 100:  3511 Killed
>    "${IONICE_CMD[@]}" "${NICE_CMD[@]}" "${NETNS_CMD[@]}" "${CHBIND_CMD[@]}"
> "$_VSPACE" --enter "$S_CONTEXT" "${OPTS_VSPACE[@]}"
> "${OPTS_VSPACE_SHARED[@]}" -- "$_VTAG" --migrate "${OPTS_VTAG_ENTER[@]}"
> --silent -- $_VCONTEXT $SILENT_OPT --migrate $OPT_VCONTEXT_CHROOT --xid
> "$S_CONTEXT" -- "${INITCMD_STOP[@]}"

This looks like the rc scripts executed to stop the guest
kill the util-vserver stop script at some point.

> This doesn't happen with wheezy guests running on jessie hosts,

This is kind of suspected, as it is most likely a minor
"problem" with the guest side rc scripts.

> or with jessie guests on wheezy hosts. 

This is very interesting, are you sure that the very
same guest does not exhibit this behaviours regardless
of the host system (given that util-vserver is the same
version).

> If I switch from init style sysv to plain, I don't see any
> errors, but I'm assuming that just suppresses the message 
> since the vserver shuts down almost instantaneously; 

An almost instant shutdown is not a bad thing per se, after
all container style virtualization is very fast. This
setup will not call any scripts inside the guest directly,
instead it will signal the init process inside the guest
to shut down. If everything goes as expected, your guest
should simply disappear (no more processes in the guest 
context)

> I'm concerned that it's not going down cleanly.

It might be a good idea to check what scripts are actually
executed inside the guest and supplement them with debug
output (or run them with -x for bash scripts).

> The kernel version for jessie is 3.18.21-vs2.3.7.4-beng (from
> repo.psand.net), util-vserver is 0.30.216-pre3120-jessie0.1-1.

> Any hints on how to fix or at least debug this?

You can also run util-vserver with the --debug option,
which might shed some light on the issue.

HTH,
Herbert