some (random) jails are not started after reboot

[James Gritton]

On 2016-10-06 06:01, Miroslav Lachman wrote:
> Hi,
> 
> we have a few machines running jails as "vps". All jails are
> maintained by me and have normal setup with one IPv4. We are running
> usual web things in jails like Apache, PHP, Python, MySQL.
> 
> I noticed that some jails are not started after reboot on one machine.
> (after security update to 10.3-RELEASE-p6 in the summer)
> I updated our machines last night to 10.3-RELEASE-p9 and one jail on
> the same machine did not start.
> Console log of this jail does not contain any startup messages. The
> last record are from previous start.
> I can start the jail manually without any problem. No errors.
> 
> Only one machine has this problem. Problem started a few months back.
> (The machine was started as some old 8.x install and is continually
> upgraded to the latest 10.3)
> Base system is on UFS, jails are on ZFS if it matter.
> 
> This is production machine so I can't play with it too much. But does
> anybody else seen it too?
> How can I debug it on next reboot?

Two handy things.  One is to make sure every jail has an exec.consolelog 
file set, so if it gets partway through startup and then goes away, you 
can see what it did up until then.  Second is the "-v" flag to jail(8).  
Add it to jail_flags in your rc.conf, and then comment out the bit in 
/etc/rc.d/jail that removes the temp file for jail(8)'s output ($_tmp).  
Watch out for parallel starts - they just went to /dev/null until 
recently.

- Jamie