So I tried db_mode 3 and it worked the first time. Phones registered and USRLOC wrote to the location table successfully.
Stopped the service and then attempted to start again, and the time-out crash occurred. Tried once more, and it still crashed (however, the segfaults are different).
Crash 1:
Sep 12 09:52:20 vpsl32n011 kernel: [836803.080856] kamailio[8116]: segfault at 0 ip (null) sp 00007fff1030aa68 error 14 in kamailio[400000+42e000]
Crash 2:
Sep 12 09:58:21 vpsl32n011 kernel: [837164.256390] kamailio[8220]: segfault at 7fdc518b1000 ip 00007fdc5740ce3e sp 00007fff40f0e118 error 4 in libc-2.19.so[7fdc572c5000+1a1000]
Here is syslog for both crashes and core dump for the last one (accidentally overwrote the corefile from first).
[Crash1_Syslog.txt](https://github.com/kamailio/kamailio/files/1296451/Crash1_Syslog.txt) [Crash2_Core.txt](https://github.com/kamailio/kamailio/files/1296452/Crash2_Core.txt) [Crash2_Syslog.txt](https://github.com/kamailio/kamailio/files/1296453/Crash2_Syslog.txt)