Assertion failed

Running FreeBSD 7.2 on 8.4

Just before this weekend we had some issues with an old server which had lost one of the disks in it’s mirror and the second was starting to fail. This is a server we plan to decommission, but unfortunately we can’t do this yet as it still has a lot of important services running. This server was running an FreeBSD 7.2 and thankfully all services we care about was running in a jail. So it was decided, to get a temporary solution to this, we would create a new FreeBSD 8.4 virtual machine and move the jail as is to the new machine.

From my earlier experience with running 9.x on 10 I expected this to go like a charm, but unfortunately this was not the case. After several ours of transfering the jail to the new host, the time had finally come to start it. It started just as expected, but some of the services did not come up. More specifically stunnel and mysql. After some debugging it turned out they both failed on the function ‘kse_create’. This function is a part of the kernel supported user threads (kse(2)). Support for these was removed with FreeBSD 8, and since I was staying with the 7.2 userland in the jail it was not just to recompile the affected programs in the jail.

To solve this I recompiled the affected programs for 8.4, before I installed them to the 7.2 jail. This did have one problem though, the binary was linked against libraries which wasn’t available in FreeBSD 7.2. The natural solution for this would be the compat8x port, but it contained a lot of libraries which wasn’t necessary and was lacking a few which was needed. So instead of using compat8x, I chose to manually copy the missing libraries from the 8.4 machine and install them to the 7.2 jail. Then after some compiling the services which originally used kse was back up again without it.

Running poudriere in a jail

Poudriere is a great tool when you need to build packages for freebsd, but sometimes one would prefer to run it in a jail. Even though this is not recomended there is a basic guide for how to do this on the poudriere wiki. But this does not work if your poudriere jail is configured with an ip-address instead of inheriting ip-addresses.

In addition to the settings shown in the guide one would have to add the following to poudriere.conf:

LOIP4="192.168.1.10/24" # IPv4 of jail
LOIP6="fec0::10/64"     # IPv6 of jail

But there is still one caveat left to discover. If your kernel supports IPv4/6 and the jail does not have an IPv4/6-address it will fail. This problem can be solved with the following patch assuming you use poudriere 3.1-pre (your miles may wary with other versions).

diff --git a/src/share/poudriere/common.sh b/src/share/poudriere/common.sh
index 6a78e37..ef91e4b 100755
--- a/src/share/poudriere/common.sh
+++ b/src/share/poudriere/common.sh
@@ -4341,6 +4341,13 @@ fi

 : ${LOIP6:=::1}
 : ${LOIP4:=127.0.0.1}
+
+[ "${LOIP4}" = "no" ] && \
+       IPS="0$(echo $IPS | tail -c 1)"
+
+[ "${LOIP6}" = "no" ] && \
+       IPS="$(echo $IPS | head -c 1)0"
+
 case $IPS in
 01)
        localipargs="ip6.addr=${LOIP6}"

After applying this patch you can use the following in poudriere.conf to disable IPv4 and/or IPv6:

LOIP4="no" # Disable IPv4
LOIP6="no" # Disable IPv6

What you will probably want is something similar to the following:

LOIP4="192.168.1.10/24" # IPv4 of jail
LOIP6="no"              # Disable IPv6

or:

LOIP4="no"          # Disable IPv4
LOIP6="fec0::10/64" # IPv6 of jail

Note: When disabling either IPv4 or IPv6 ‘no’ is case sensitive when using this pathch.