Dec 6 15:20:49 dhcpd: DHCPREQUEST for 192.168.0.62 (192.168.0.254) from 14:7d:c5:18:9e:8f (android-2dc1463dcd3fbd17) via em0: database update failed

Doing some digging I believe this is due to the /var filesystem being full.
login as: admin
Using keyboard-interactive authentication.
Password:

/var: write failed, filesystem is full
*** Welcome to pfSense 2.1-RELEASE-pfSense (amd64) on pfsense ***

[2.1-RELEASE][admin@pfsense.local]/var/log(8): df -h
Filesystem    Size    Used  Avail Capacity  Mounted on
/dev/ad4s1a    217G    1.6G    198G    1%    /
devfs          1.0k    1.0k      0B  100%    /dev
/dev/md0      495M    646k    455M    0%    /tmp
/dev/md1      495M    495M    -39M  109%    /var
devfs          1.0k    1.0k      0B  100%    /var/dhcpd/dev

[2.1-RELEASE][admin@pfsense.local]/var(16): du -h /var/
2.0k    /var/.snap
2.0k    /var/db/entropy
7.5M    /var/db/rrd
2.0k    /var/db/ntop/rrd/graphics
2.0k    /var/db/ntop/rrd/flows
3.7M    /var/db/ntop/rrd/interfaces/em0
3.7M    /var/db/ntop/rrd/interfaces
3.8M    /var/db/ntop/rrd
475M    /var/db/ntop
2.0k    /var/db/pingstatus
2.0k    /var/db/pingmsstatus
483M    /var/db
46k    /var/tmp
46k    /var/run
2.0k    /var/log/ntp
9.3M    /var/log
2.0k    /var/etc/openvpn
2.0k    /var/etc/openvpn-csc
2.0k    /var/etc/l2tp-vpn
44k    /var/etc
2.0k    /var/at/jobs
4.0k    /var/at
2.0k    /var/empty
2.0k    /var/dhcpd/var/run
2.0k    /var/dhcpd/var/db
6.0k    /var/dhcpd/var
512B    /var/dhcpd/dev/fd
512B    /var/dhcpd/dev/led
512B    /var/dhcpd/dev/usb
512B    /var/dhcpd/dev/pts
2.5k    /var/dhcpd/dev
4.0k    /var/dhcpd/etc
1.8M    /var/dhcpd/usr/local/sbin
1.8M    /var/dhcpd/usr/local
1.8M    /var/dhcpd/usr
1.2M    /var/dhcpd/lib
2.0k    /var/dhcpd/run
3.0M    /var/dhcpd
2.0k    /var/cron/tabs
4.0k    /var/cron
495M    /var/

I thought this might be useful output, since it seemed quite easy for me to unintentionally exceed my disk partition size.