rhel7: system wont boot, dracut messages "fork: Cannot allocate memory"

Issue

• We have a RHEL7 server that wont boot, see attached image for failure. We see dracut messages "fork: Cannot allocate memory".
• I see this, booting rhel7:

[  OK  ] Reached target Swap.
         Starting Remount Root and Kernel File Systems...
[  OK  ] Stopped Trigger Flushing of Journal to Persistent Storage.
         Stopping Journal Service...
[  OK  ] Stopped Journal Service.
         Starting Journal Service...
[FAILED] Failed to start Journal Service.
See 'systemctl status systemd-journald.service' for details.
[DEPEND] Dependency failed for Trigger Flushing of Journal to...istent Storage.
[  OK  ] Mounted Debug File System.
[FAILED] Failed to start Create list of required static devic...current kernel.
See 'systemctl status kmod-static-nodes.service' for details.
[FAILED] Failed to mount POSIX Message Queue File System.
See 'systemctl status dev-mqueue.mount' for details.
[FAILED] Failed to mount Huge Pages File System.
See 'systemctl status dev-hugepages.mount' for details.
[FAILED] Failed to start Monitoring of LVM2 mirrors, snapshot...ogress polling.
See 'systemctl status lvm2-monitor.service' for details.