[Motorola Photon Q 4G LTE] AndyYan:
It's okay, if there were any important data there I would have backed it up before you say it. And yes, /sdcard simply symlinks to /data/media.

As I described, I can flash ROMs all I want, yet I can't backup or wipe my /data, which is needed for backup ops.

Here's the full output:

~ # mount
mount
rootfs on / type rootfs (rw)
tmpfs on /dev type tmpfs (rw,nosuid,relatime,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
/dev/block/mmcblk0p36 on /cache type ext4 (rw,relatime,user_xattr,barrier=1,data=ordered)
[B]/dev/block/mmcblk0p39 on /data type ext4 (rw,relatime,user_xattr,barrier=1,data=ordered)[/B]
/dev/block/mmcblk0p39 on /sdcard type ext4 (rw,relatime,user_xattr,barrier=1,data=ordered)
/dev/block/mmcblk1p1 on /external_sdcard type vfat (rw,relatime,fmask=0000,dmask=0000,allow_utime=0022,codepage=cp437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)

~ # ls -al /dev/block/platform/msm_sdcc.1/by-name
ls -al /dev/block/platform/msm_sdcc.1/by-name
lrwxrwxrwx root root 2014-05-18 00:52 aboot -> /dev/block/mmcblk0p5
lrwxrwxrwx root root 2014-05-18 00:52 abootBackup -> /dev/block/mmcblk0p12
lrwxrwxrwx root root 2014-05-18 00:52 boot -> /dev/block/mmcblk0p31
lrwxrwxrwx root root 2014-05-18 00:52 cache -> /dev/block/mmcblk0p36
lrwxrwxrwx root root 2014-05-18 00:52 carriercust -> /dev/block/mmcblk0p35
lrwxrwxrwx root root 2014-05-18 00:52 cdrom -> /dev/block/mmcblk0p38
lrwxrwxrwx root root 2014-05-18 00:52 cid -> /dev/block/mmcblk0p28
lrwxrwxrwx root root 2014-05-18 00:52 devtree -> /dev/block/mmcblk0p30
lrwxrwxrwx root root 2014-05-18 00:52 dhob -> /dev/block/mmcblk0p21
lrwxrwxrwx root root 2014-05-18 00:52 fsg -> /dev/block/mmcblk0p24
lrwxrwxrwx root root 2014-05-18 00:52 hob -> /dev/block/mmcblk0p20
lrwxrwxrwx root root 2014-05-18 00:52 kpan -> /dev/block/mmcblk0p33
lrwxrwxrwx root root 2014-05-18 00:52 logo -> /dev/block/mmcblk0p29
lrwxrwxrwx root root 2014-05-18 00:52 mbl -> /dev/block/mmcblk0p19
lrwxrwxrwx root root 2014-05-18 00:52 misc -> /dev/block/mmcblk0p26
lrwxrwxrwx root root 2014-05-18 00:52 modem -> /dev/block/mmcblk0p1
lrwxrwxrwx root root 2014-05-18 00:52 modemst1 -> /dev/block/mmcblk0p17
lrwxrwxrwx root root 2014-05-18 00:52 modemst2 -> /dev/block/mmcblk0p18
lrwxrwxrwx root root 2014-05-18 00:52 padA -> /dev/block/mmcblk0p9
lrwxrwxrwx root root 2014-05-18 00:52 padB -> /dev/block/mmcblk0p16
lrwxrwxrwx root root 2014-05-18 00:52 pds -> /dev/block/mmcblk0p27
lrwxrwxrwx root root 2014-05-18 00:52 persist -> /dev/block/mmcblk0p22
lrwxrwxrwx root root 2014-05-18 00:52 recovery -> /dev/block/mmcblk0p32
lrwxrwxrwx root root 2014-05-18 00:52 rpm -> /dev/block/mmcblk0p6
lrwxrwxrwx root root 2014-05-18 00:52 rpmBackup -> /dev/block/mmcblk0p13
lrwxrwxrwx root root 2014-05-18 00:52 sbl1 -> /dev/block/mmcblk0p2
lrwxrwxrwx root root 2014-05-18 00:52 sbl2 -> /dev/block/mmcblk0p3
lrwxrwxrwx root root 2014-05-18 00:52 sbl2Backup -> /dev/block/mmcblk0p10
lrwxrwxrwx root root 2014-05-18 00:52 sbl3 -> /dev/block/mmcblk0p4
lrwxrwxrwx root root 2014-05-18 00:52 sbl3Backup -> /dev/block/mmcblk0p11
lrwxrwxrwx root root 2014-05-18 00:52 sp -> /dev/block/mmcblk0p25
lrwxrwxrwx root root 2014-05-18 00:52 ssd -> /dev/block/mmcblk0p23
lrwxrwxrwx root root 2014-05-18 00:52 system -> /dev/block/mmcblk0p37
lrwxrwxrwx root root 2014-05-18 00:52 tombstones -> /dev/block/mmcblk0p34
lrwxrwxrwx root root 2014-05-18 00:52 tz -> /dev/block/mmcblk0p7
lrwxrwxrwx root root 2014-05-18 00:52 tzBackup -> /dev/block/mmcblk0p14
[B]lrwxrwxrwx root root 2014-05-18 00:52 userdata -> /dev/block/mmcblk0p39[/B]
lrwxrwxrwx root root 2014-05-18 00:52 utags -> /dev/block/mmcblk0p8
lrwxrwxrwx root root 2014-05-18 00:52 utagsBackup -> /dev/block/mmcblk0p15

~ # ls -al /dev/block/mmcblk0p39
ls -al /dev/block/mmcblk0p39
brw------- root root 259, 7 2014-05-18 00:52 mmcblk0p39

As you can see, /data and userdata both exists.

Furthermore, using TWRP, I can even use its file manager to delete files, modify permissions, etc. in /data, just can't wipe it or back it up (backing up /data usually takes 20+ seconds, but now it's completed in a flash).