Upgrading FBSD-7.0 --> 7.4 and Jail won't start

[Jack Stone]

uname -a
FreeBSD mail.sagedata.net 7.0-RELEASE-p9 FreeBSD 7.0-RELEASE-p9 #2: 
Sun Jan 18 19:59:27 CST 2009 
root at mail.sagedata.net:/usr/obj/usr/src/sys/SMP  i386

Have been running and upgrading host+jail for years and through several versions of FreeBSD. However, I got behind on updates and now playing catchup on an important production server.

Tried to upgrade fbsd-7.0 --> 7.4 followed by upgarde of a jail as in past. However, on reboot, the host booted up OK, but the jail would not work. On re-trying to start the jail, only got a crytic error about missing syscalls. I've never seen this before and don't have a clue what needs fixing.

My setups for starting jails are in the /etc/rc.conf file and such still works here in Texas on local servers when upgraded. However, the production server is in Los Angeles and cannot react to any serious boot problems without sending the ISP owner downtown to switch my HD back to a bootable clone before the upgrade attempts. I cannot afford to have the jail offline as it contains my SSL stuff vital to the business.

I manage the jails using the tools that came with Jail(8).

Can anyone point me in the right direction on this issue? Do I now need stuff in sysctl.conf for the jail? Or.....????

Thanks for any help!!

--
All the best,
Jack