./busybox fdisk -l /dev/block/mmcblk0

Disk /dev/block/mmcblk0: 15.7 GB, 15756951552 bytes
1 heads, 16 sectors/track, 1923456 cylinders
Units = cylinders of 16 * 512 = 8192 bytes

              Device Boot      Start         End      Blocks  Id System
/dev/block/mmcblk0p1               1       12801      102400  92 Unknown
Partition 1 does not end on cylinder boundary
/dev/block/mmcblk0p2   *       12801       12863         500  4d Unknown
Partition 2 does not end on cylinder boundary
/dev/block/mmcblk0p3           12863       13051        1500  51 Unknown
Partition 3 does not end on cylinder boundary
/dev/block/mmcblk0p4           13051     1923584    15284271+  5 Extended
Partition 4 does not end on cylinder boundary
/dev/block/mmcblk0p5           13313       13375         500  47 Unknown
/dev/block/mmcblk0p6           13825       14080        2048  45 Unknown
/dev/block/mmcblk0p7           14337       14649        2500  4c Unknown
/dev/block/mmcblk0p8           14849       16128       10240  48 Unknown
/dev/block/mmcblk0p9           16385       16447         500  46 Unknown
/dev/block/mmcblk0p10          16897       16959         500  5d Unknown
/dev/block/mmcblk0p11          17409       17471         500  91 Unknown
/dev/block/mmcblk0p12          17921       19200       10240  93 Unknown
/dev/block/mmcblk0p13          19457       32000      100352   c Win95 FAT32 (LBA)
/dev/block/mmcblk0p14          32257       32640        3072  4a Unknown
/dev/block/mmcblk0p15          32769       33152        3072  4b Unknown
/dev/block/mmcblk0p16          33281       33664        3072  58 Unknown
/dev/block/mmcblk0p17          33793       46336      100352  8f Unknown
/dev/block/mmcblk0p18          46593       46976        3072  59 Unknown
/dev/block/mmcblk0p19          47105       47488        3072  5a Unknown
/dev/block/mmcblk0p20          47617       48000        3072  5b Unknown
/dev/block/mmcblk0p21          48129       49408       10240  ab Darwin boot
/dev/block/mmcblk0p22          49665       50944       10240  60 Unknown
/dev/block/mmcblk0p23          51201       52480       10240  94 Unknown
/dev/block/mmcblk0p24          52737      137472      677888  a5 FreeBSD
/dev/block/mmcblk0p25         137729      400128     2099200  a6 OpenBSD
/dev/block/mmcblk0p26         400385      439040      309248  a8 Darwin UFS
/dev/block/mmcblk0p27         439297      455808      132096  a9 NetBSD
/dev/block/mmcblk0p28         456193     1923584    11739136  90 Unknown
/data/data/com.spartacusrex.spartacuside/files/system/bin #

Note the last partition is, indeed, broken. Is it used?

/dev/block/vold/179:28
                         11.0G    959.1M     10.1G   9% /mnt/sdcard

/data/data/com.spartacusrex.spartacuside/files/system/bin # ls -l /dev/block/vold/
total 1
brw-r-----    1 root     sdcard_r  179,  28 Mar 29 08:35 179:28
brw-r-----    1 root     sdcard_r  179,  32 Mar 29 08:35 179:32
brw-r-----    1 root     sdcard_r  179,  33 Mar 29 08:36 179:33

data/data/com.spartacusrex.spartacuside/files/system/bin # ls -l /dev/block/mmcblk0p28
brw-------    1 root     root      179,  28 Mar 29 08:35 /dev/block/mmcblk0p28
/data/data/com.spartacusrex.spartacuside/files/system/bin #

This means that this phone has a fucked partition table by design, and if you fill up your internal storage you WILL kill the phone.