[Nexus 6 Q&A, Help & Troubleshooting] ScottIsMyName:
Here is the result of me listing all files in /persist:

1|root@shamu:/persist # find . -exec ls -dl \{\} \;
find . -exec ls -dl \{\} \;
drwxrwx--x 15 system system 4096 1969-12-31 21:22 .
drwx------ 2 root root 4096 1969-12-31 16:00 ./lost+found
drwxrwxr-x 2 nobody nobody 4096 2014-11-03 23:53 ./sensors
-rw-rw-r-- 1 system root 2 2014-11-04 00:02 ./sensors/sensors_settings
-rwx------ 1 root root 14592 2016-04-11 03:00 ./sensors/sns.reg
-rw------- 1 root root 0 2014-11-03 23:53 ./sensors/error_log
drwxr-sr-x 2 9004 camera 4096 1969-12-31 16:03 ./camera
drwxr-xr-x 2 9004 9004 4096 2014-11-03 23:53 ./factory
-rw------- 1 9004 9004 128 2014-11-03 23:55 ./factory/fti
drwxr-xr-x 8 system radio 4096 1969-12-31 16:03 ./public
drwxrwx--- 2 9012 shell 4096 1969-12-31 16:03 ./public/atvc
drwxr-xr-x 2 9000 9004 4096 1969-12-31 16:03 ./public/battd
drwxrwxr-x 3 system radio 4096 2015-07-30 18:21 ./public/hiddenmenu
drwxrwxr-x 2 system radio 4096 2015-07-30 16:31 ./public/hiddenmenu/data
-rw-r--r-- 1 radio radio 8 2016-04-09 11:12 ./public/hiddenmenu/data/mobile_data_rx
-rw-r--r-- 1 radio radio 8 2016-04-09 11:12 ./public/hiddenmenu/data/mobile_data_tx
-rw-r--r-- 1 radio radio 8 2016-04-09 11:12 ./public/hiddenmenu/data/wifi_data_rx
-rw-r--r-- 1 radio radio 8 2016-04-09 11:12 ./public/hiddenmenu/data/wifi_data_tx
-rw-r--r-- 1 radio radio 4 2016-04-12 09:47 ./public/hiddenmenu/life_calls
-rw-r--r-- 1 radio radio 8 2016-04-12 09:47 ./public/hiddenmenu/life_timer
drwx------ 2 system system 4096 1969-12-31 16:03 ./public/locale
drwxrwx--- 2 system 9004 4096 1969-12-31 16:03 ./public/svcs
drwx------ 2 radio radio 4096 1969-12-31 16:03 ./public/omadm
drwxr-xr-x 2 9004 9004 4096 1969-12-31 16:03 ./wifi
drwxr-xr-x 2 9004 bluetooth 4096 1969-12-31 16:03 ./bt
drwxrwxr-x 2 9003 9003 4096 1969-12-31 16:03 ./wmdrm
drwxrws--- 2 9007 9007 4096 2014-12-14 13:31 ./security
-rw-rw-r-- 1 9004 9007 608 2014-12-14 13:31 ./security/keymaptable.dat
drwxrws--- 3 9004 9009 4096 1969-12-31 16:03 ./whisper
drwx------ 2 9009 9009 4096 1969-12-31 16:03 ./whisper/whisper_only
drwxr-xr-x 2 9001 9001 4096 1969-12-31 16:03 ./batt_health
-rw-r----- 1 9001 9001 32 1969-12-31 16:03 ./batt_health/batt-0123456789abcdef_0
-r-------- 1 root root 0 1969-12-31 16:03 ./pds_formatted_v12
-rw------- 1 wifi system 13 1969-12-31 16:03 ./wlan_mac_serial.bin
drwx------ 4 system system 4096 2014-12-14 13:31 ./data
drwx------ 2 system system 4096 2014-12-14 13:32 ./data/sfs
-rwx------ 1 system system 1336 2014-12-14 13:31 ./data/sfs/Z44f4P4bbdZAgGPLCbm6Dfq4NfI_
-rwx------ 1 system system 1336 2014-12-14 13:31 ./data/sfs/kTS2rn3shHvYCwlQtj-6N3tMBHc_
-rwx------ 1 system system 1336 2014-12-14 13:31 ./data/sfs/aTH8Io+wqbi-p8ML6VZav8VAZmg_
-rwx------ 1 system system 1336 2014-12-14 13:32 ./data/sfs/Womhybvq54YMKrypTs5xbu7F1lg_
-rwx------ 1 system system 1336 2014-12-14 13:32 ./data/sfs/KJG4O0oOJ4bJNAfv8QST3JrENMk_
drwx------ 2 system system 4096 2014-12-14 13:31 ./data/tz
-rwx------ 1 system system 208 2014-12-14 13:32 ./data/tz/tz_counter
-rwx------ 1 system system 208 2014-12-14 13:32 ./data/tz/tz_counter.bak
drwxrwx--- 2 radio radio 4096 2015-07-30 16:28 ./mdm
-rw------- 1 radio radio 1 1970-01-16 14:10 ./mdm/efs_img_left
-rw------- 1 radio radio 7 1970-01-16 14:10 ./mdm/customer_id
-rw------- 1 root root 1 1970-01-16 14:13 ./mdm/efs1_erasing
-rw------- 1 root root 1 1970-01-16 14:19 ./mdm/efs2_erasing
-rw-rw---- 1 radio radio 1 2016-04-10 13:47 ./mdm/efs_img_erased
-rw------- 1 radio radio 0 2016-04-10 13:47 ./mdm/nova_customer_id
-rw------- 1 radio radio 5 2016-01-28 10:09 ./mdm/oma_dm_update