[Xperia Z1 Compact Android Development] puppet13th:
it's look like XZ1c uses unified storage.

unified storage = intenal storage(/mnt/sdcard0/) --> /data/media

root@android:/storage/sdcard0 # df
Filesystem Size Used Free Blksize
/dev 343.1M 72.0K 343.0M 4096
/mnt/asec 343.1M 0.0K 343.1M 4096
/mnt/obb 343.1M 0.0K 343.1M 4096
/system 1009.3M 877.7M 131.6M 4096
[COLOR="Red"]/data 3.9G 1.3G 2.6G 4096[/COLOR]
/cache 246.2M 4.3M 241.9M 4096
/data/idd 7.5M 1.1M 6.4M 1024
[COLOR="red"]/storage/sdcard0 3.9G 1.3G 2.6G 4096[/COLOR]
/mnt/asec/com.keramidas.TitaniumBackupPro-1 2.0M 80.0K 1.9M 4096
/mnt/asec/com.mobisystems.editor.office_registered-1 50.0M 48.7M 1.3M 4096
/mnt/asec/com.quoord.tapatalkHD-2 31.0M 29.2M 1.9M 4096
/storage/sdcard1 29.7G 27.8G 1.9G 32768
root@android:/storage/sdcard0 #

mounts :

root@android:/storage/sdcard0 # mount
rootfs / rootfs ro,relatime 0 0
tmpfs /dev tmpfs rw,nosuid,noatime,nodiratime,mode=755 0 0
devpts /dev/pts devpts rw,noatime,nodiratime,mode=600 0 0
proc /proc proc rw,noatime,nodiratime 0 0
sysfs /sys sysfs rw,noatime,nodiratime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
tmpfs /mnt/asec tmpfs rw,noatime,nodiratime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,noatime,nodiratime,mode=755,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
/dev/block/platform/msm_sdcc.1/by-num/p12 /system ext4 ro,relatime,noauto_da_alloc,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-num/p14 /data ext4 rw,nosuid,nodev,noatime,nodiratime,nobarrier,noauto_da_alloc,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-num/p13 /cache ext4 rw,nosuid,nodev,noatime,nodiratime,nobarrier,noauto_da_alloc,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-num/p10 /data/idd ext4 rw,nosuid,nodev,noatime,nobarrier,data=ordered 0 0
[COLOR="Red"]/dev/fuse /storage/sdcard0 fuse rw,nosuid,nodev,noexec,noatime,nodiratime,user_id=1023,group_id=1023,default_permissions,allow_other 0 0[/COLOR]
/dev/block/dm-0 /mnt/asec/com.keramidas.TitaniumBackupPro-1 ext4 ro,nosuid,nodev,relatime 0 0
/dev/block/dm-1 /mnt/asec/com.mobisystems.editor.office_registered-1 ext4 ro,nosuid,nodev,relatime 0 0
/dev/block/dm-2 /mnt/asec/com.quoord.tapatalkHD-2 ext4 ro,nosuid,nodev,relatime 0 0
/dev/block/vold/179:33 /storage/sdcard1 vfat rw,dirsync,nosuid,nodev,noexec,relatime,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

from /system/build.prop

# It is changed to true in msm8660_surf
# Change it back to false according to blue
#
# Simulate sdcard on /data/media
#
[B][COLOR="Red"]persist.fuse_sdcard=false[/COLOR][/B]

this example i take from lt26w build.prop the value should be true for XZ1c.

/init.semc.rc

# msm specific files that need to be created on /data
on post-fs-data
# we will remap this as /mnt/sdcard with the sdcard fuse tool
mkdir /data/media 0775 media_rw media_rw
chown media_rw media_rw /data/media
mkdir /data/media/Download 0775 media_rw media_rw
chown media_rw media_rw /data/media/Download

/init.sony-device.rc

# User 2800: sdcardd
service sdcardd /system/bin/sdcard /mnt/int_storage 2800 2800
user root
group sdcard_rw
disabled

/system/bin/sdcard --> binary to fuse mount /data/media to /mnt/int_storage

i have managed to enable unified storage on lt26w by editing the build.prop and vold.fstab.hopefully this could help with internal storage mounts on XZ1c.