@kugiigi Thanks, I will check that project, seems it's more suitable for me.

@kugiigi Thanks for the reply, I already gave up on that, it's too risky to do that. And I don't think it's a good idea to resize a filesystem unlike the loop

@mateo_salta correct, I am trying to use it as a micro server like raspberry pi, so APT installations are required. I have mapped soft link to some directory like apt cache to avoid run out of space, and trying not to install more.

It's so great we have a place to seeking the help. My partition is super wired that I don't know where to start.

My phone is Xiaomi6 (AKA mi A2), the Ubuntu touch is version 16, latest dev version.

And I have seen many people extend their partition by extending the system.img or ubuntu.img etc.

But I can't find any img file related to the root partition.

Here is df -h:

root@ubuntu-phablet:/userdata# df -h
Filesystem                     Size  Used Avail Use% Mounted on
udev                           2.7G  828K  2.7G   1% /dev
tmpfs                          569M  1.5M  567M   1% /run
/dev/sda17                     110G  8.7G   96G   9% /userdata
/dev/disk/by-partlabel/system  4.9G  3.0G  1.9G  63% /
/dev/loop0                     533M  459M   63M  89% /android
tmpfs                          2.8G  4.0K  2.8G   1% /etc/fstab
none                           4.0K     0  4.0K   0% /sys/fs/cgroup
tmpfs                          2.8G  5.8M  2.8G   1% /tmp
none                           5.0M     0  5.0M   0% /run/lock
none                           2.8G  180K  2.8G   1% /run/shm
none                           100M     0  100M   0% /run/user
cgmfs                          100K     0  100K   0% /run/cgmanager/fs
tmpfs                          2.8G     0  2.8G   0% /media
tmpfs                          2.8G     0  2.8G   0% /var/lib/openvpn/chroot/tmp
tmpfs                          2.8G     0  2.8G   0% /var/lib/sudo
/dev/sde42                     460M  323M  128M  72% /android/vendor
tmpfs                          2.8G     0  2.8G   0% /mnt
/dev/sda14                      28M  4.7M   23M  18% /mnt/vendor/persist
/dev/sde37                      12M   11M  1.5M  88% /android/vendor/dsp
/dev/sde41                     192M  109M   84M  57% /android/vendor/firmware_mnt
/dev/sde32                      64M  368K   64M   1% /android/vendor/bt_firmware
tmpfs                          569M   72K  569M   1% /run/user/32011
tmpfs                          569M     0  569M   0% /run/user/0

Here is fdisk -l:

root@ubuntu-phablet:/userdata# fdisk -l
Disk /dev/ram0: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram1: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram2: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram3: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram4: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram5: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram6: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram7: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram8: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram9: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram10: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram11: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram12: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram13: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram14: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/ram15: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes


Disk /dev/loop0: 549.3 MiB, 575950848 bytes, 1124904 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/sda: 112.6 GiB, 120896618496 bytes, 29515776 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
Disklabel type: gpt
Disk identifier: 98101B32-BBE2-4BF2-A06E-2BB33D000C20

Device      Start      End  Sectors   Size Type
/dev/sda1       6        7        2     8K Linux filesystem
/dev/sda2       8       15        8    32K unknown
/dev/sda3      16      127      112   448K Linux filesystem
/dev/sda4     128      191       64   256K Linux filesystem
/dev/sda5     192      255       64   256K Linux filesystem
/dev/sda6     256      383      128   512K unknown
/dev/sda7     384      511      128   512K unknown
/dev/sda8     512     1023      512     2M Linux filesystem
/dev/sda9    1024     2047     1024     4M unknown
/dev/sda10   2048     4095     2048     8M unknown
/dev/sda11   4096     8191     4096    16M unknown
/dev/sda12   8192    12287     4096    16M Linux filesystem
/dev/sda13  12288    16383     4096    16M Linux filesystem
/dev/sda14  16384    32767    16384    64M unknown
/dev/sda15  32768    49151    16384    64M unknown
/dev/sda16  49152   114687    65536   256M unknown
/dev/sda17 114688 29515770 29401083 112.2G unknown

Partition 1 does not start on physical sector boundary.
Partition 2 does not start on physical sector boundary.


Disk /dev/sdb: 8 MiB, 8388608 bytes, 2048 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
Disklabel type: gpt
Disk identifier: 98101B32-BBE2-4BF2-A06E-2BB33D000C20

Device     Start   End Sectors Size Type
/dev/sdb1      6  2042    2037   8M unknown

Partition 1 does not start on physical sector boundary.


Disk /dev/sdc: 8 MiB, 8388608 bytes, 2048 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
Disklabel type: gpt
Disk identifier: 98101B32-BBE2-4BF2-A06E-2BB33D000C20

Device     Start   End Sectors Size Type
/dev/sdc1      6  2042    2037   8M unknown

Partition 1 does not start on physical sector boundary.


Disk /dev/sdd: 128 MiB, 134217728 bytes, 32768 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
Disklabel type: gpt
Disk identifier: 98101B32-BBE2-4BF2-A06E-2BB33D000C20

Device     Start   End Sectors  Size Type
/dev/sdd1      6    13       8   32K unknown
/dev/sdd2     14   247     234  936K Linux filesystem
/dev/sdd3    248   255       8   32K unknown
/dev/sdd4    256   511     256    1M unknown
/dev/sdd5    512   767     256    1M Linux filesystem
/dev/sdd6    768 32762   31995  125M unknown

Partition 1 does not start on physical sector boundary.
Partition 2 does not start on physical sector boundary.
Partition 3 does not start on physical sector boundary.


Disk /dev/sdf: 128 MiB, 134217728 bytes, 32768 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
Disklabel type: gpt
Disk identifier: 98101B32-BBE2-4BF2-A06E-2BB33D000C20

Device     Start   End Sectors  Size Type
/dev/sdf1      6     7       2    8K unknown
/dev/sdf2      8   255     248  992K Linux filesystem
/dev/sdf3    256   511     256    1M Linux filesystem
/dev/sdf4    512  2559    2048    8M unknown
/dev/sdf5   2560  4607    2048    8M unknown
/dev/sdf6   4608  4863     256    1M Linux filesystem
/dev/sdf7   4864 32762   27899  109M unknown

Partition 1 does not start on physical sector boundary.
Partition 2 does not start on physical sector boundary.


Disk /dev/sde: 6.3 GiB, 6777995264 bytes, 1654784 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes
Disklabel type: gpt
Disk identifier: 98101B32-BBE2-4BF2-A06E-2BB33D000C20

Device       Start     End Sectors  Size Type
/dev/sde1        6       7       2    8K unknown
/dev/sde2        8      15       8   32K unknown
/dev/sde3       16      23       8   32K unknown
/dev/sde4       24      63      40  160K Linux filesystem
/dev/sde5       64     127      64  256K unknown
/dev/sde6      128     191      64  256K unknown
/dev/sde7      192     223      32  128K unknown
/dev/sde8      224     255      32  128K unknown
/dev/sde9      256     383     128  512K unknown
/dev/sde10     384     511     128  512K unknown
/dev/sde11     512     767     256    1M unknown
/dev/sde12     768    1023     256    1M unknown
/dev/sde13    1024    1279     256    1M unknown
/dev/sde14    1280    1535     256    1M unknown
/dev/sde15    1536    2559    1024    4M unknown
/dev/sde16    2560    3583    1024    4M unknown
/dev/sde17    3584    3839     256    1M unknown
/dev/sde18    3840    4095     256    1M unknown
/dev/sde19    4096    4351     256    1M unknown
/dev/sde20    4352    4607     256    1M unknown
/dev/sde21    4608    4863     256    1M unknown
/dev/sde22    4864    5119     256    1M unknown
/dev/sde23    5120    5631     512    2M unknown
/dev/sde24    5632    6143     512    2M unknown
/dev/sde25    6144    7167    1024    4M unknown
/dev/sde26    7168    8191    1024    4M unknown
/dev/sde27    8192    8703     512    2M unknown
/dev/sde28    8704    8767      64  256K unknown
/dev/sde29    8768    8831      64  256K unknown
/dev/sde30    8832    9215     384  1.5M Linux filesystem
/dev/sde31    9216    9471     256    1M unknown
/dev/sde32    9472    9727     256    1M unknown
/dev/sde33    9728   10239     512    2M unknown
/dev/sde34   10240   12287    2048    8M unknown
/dev/sde35   12288   16383    4096   16M unknown
/dev/sde36   16384   24575    8192   32M Linux filesystem
/dev/sde37   24576   32767    8192   32M unknown
/dev/sde38   32768   40959    8192   32M unknown
/dev/sde39   40960   49151    8192   32M unknown
/dev/sde40   49152   65535   16384   64M unknown
/dev/sde41   65536  114687   49152  192M Microsoft basic data
/dev/sde42  114688  327679  212992  832M Linux filesystem
/dev/sde43  327680 1638399 1310720    5G unknown
/dev/sde44 1638400 1642495    4096   16M Linux filesystem
/dev/sde45 1642496 1654778   12283   48M unknown

Partition 1 does not start on physical sector boundary.
Partition 2 does not start on physical sector boundary.
Partition 4 does not start on physical sector boundary.

The /userdata dir doesn't contain any img file, though loseup have such outputs:

root@ubuntu-phablet:/userdata# losetup
NAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
/dev/loop0         0      0         0  1 /var/lib/lxc/android/android-rootfs.img

Now my rootfs will run out, I am very concerned about that, if someone could show me a way to solve this problem, I will be very appreciate that.

Thank you for your time.