vmcore not getting created on linux-4.7

[Steve Wise]

I've been trying to get crash dumps working on linux-4.7 and haven't succeeded.
The kdump kernel boots up and appears to be chugging along and then just reboots
and never creates the vmcore, and fails to create the vmcore-dmesg.txt, though
I've never seen that working on my nodes.  Below is the tail of the boot.  

Any ideas? 

Saving to the local filesystem UUID=f63753d9-74a5-4db8-9b63-2fc1ba2b5f85
e2fsck 1.42.12.wc1 (15-Sep-2014)
/dev/sda2: recovering journal
Setting free inodes count to 3490861 (was 3490926)
Setting freeEXT4-fs (sda2): mounted filesystem with ordered data mode. Opts:
 blocks count to 7307269 (was 7307159)
/dev/sda2: clean, 678867/4169728 files, 9358331/16665600 blocks
Free memory/Total memory (free %): 45936 / 112096 ( 40.9792 )
Loading SELINUX policy
SELinux:  Disabled at runtime.
audit: type=1404 audit(1466753867.960:2): selinux=0 auid=4294967295
ses=4294967295
Policy load failed, a relabel will be required on reboot
Saving vmcore-dmesg.txhpet1: lost 88 rtc interrupts
t
Missing the struct log size export
Saving vmcore-dmesg.txt failed
umount: can't umount /mnt/selinux: Invalid argument
sd 3:0:0:0: [sdb] Synchronizing SCSI cache
sd 1:0:0:0: [sda] Synchronizing SCSI cache
iw_cxgb4:0000:82:00.4: Detach
reboot: Restarting system
reboot: machine restart