[Xperia Tablet Z Q&A, Help & Troubleshooting] mr_xero:
Device: Sony Xperia Tablet Z

Model: SGP312

Android: 4.4.4

Problem started from 3 days ago. I had custom rom and had custom recovery: xzdualrecovery

I had some issue so wanted back to the official firmware. But unfortunately, i failed to restore the backup using TWRP.

So i needed to flash official firmware using Flashtool.

Didn't working Lolipop firmware so i flashed kitkat.

But the problem started after flashing firmware, that system is only Read-Only. I cannot able to use Internal Memory and also playstore not working.

So i wanted to again root and install "xzdualrecovery".

But getting error cause of the read-only issue.

Here is the log:

==============================================
= =
= XZDualRecovery =
= Maintained by [NUT] =
= =
= For Many Sony Xperia Devices! =
= =
==============================================

1. Installation on ROM rooted with SuperSU
2. Installation on ROM rooted with SuperUser
3. Installation on an unrooted (Lollipop 5.0) ROM using rootkitXperia
4. Install ADB drivers to windows
5. Open an ADB shell
6. Exit

Please choose install action.
[1,2,3,4,5,6]?1
* daemon not running. starting it now on port 5037 *
* daemon started successfully *

=============================================
Waiting for Device, connect USB cable now...
=============================================
Device found!

=============================================
Getting device and ROM info
=============================================
Device model is SGP312
Firmware is 10.5.1.A.0.292
Android version is 4.4.4

=============================================
Step2 : Sending the recovery files.
=============================================
10 KB/s (31 bytes in 0.002s)
2219 KB/s (18170 bytes in 0.007s)
163 KB/s (501 bytes in 0.002s)
1788 KB/s (12812 bytes in 0.006s)
2623 KB/s (65965 bytes in 0.024s)
771 KB/s (3159 bytes in 0.003s)
2378 KB/s (29204 bytes in 0.011s)
227 KB/s (699 bytes in 0.002s)
2406 KB/s (34473 bytes in 0.013s)
293 KB/s (1202 bytes in 0.003s)
2826 KB/s (96956 bytes in 0.033s)
3916 KB/s (870760 bytes in 0.217s)
3416 KB/s (3559894 bytes in 1.017s)
3528 KB/s (2426224 bytes in 0.671s)
2803 KB/s (14346 bytes in 0.004s)

=============================================
Step3 : Setup of dual recovery.
=============================================
Look at your device and grant supersu access!
Press any key to continue AFTER granting root access.
-rwxr-xr-x 1 shell shell 870760 Feb 22 2016 [1;32m/data/local/tmp/recovery/busybox[0m
Press any key to continue . . .
mkdir: can't create directory '/storage/sdcard1/XZDualRecovery': Read-only file system
mkdir: can't create directory '/cache/XZDualRecovery': Read-only file system
touch: /cache/XZDualRecovery/XZDR.prop: No such file or directory
grep: /cache/XZDualRecovery/XZDR.prop: No such file or directory
grep: /cache/XZDualRecovery/XZDR.prop: No such file or directory
grep: /cache/XZDualRecovery/XZDR.prop: No such file or directory
grep: /cache/XZDualRecovery/XZDR.prop: No such file or directory

##########################################################
#
# Installing XZDR version 2.8.26 RELEASE
#
#####

Temporarily disabling the RIC service, remount rootfs and /system writable to allow installation.
This firmware does not require byeselinux, will not install it.
Creating /system/.XZDualRecovery and subfolders.
Copy recovery files to system.
Copy chargemon script to system.
Copy dualrecovery.sh to system.
Copy rickiller.sh to system.
Installing NDRUtils to system.
Copy busybox to system.
Copy init's *.rc files in to /system/.XZDualRecovery.
Creating the XZDR properties file.
touch: /cache/XZDualRecovery/XZDR.prop: No such file or directory
chmod: /cache/XZDualRecovery/XZDR.prop: No such file or directory
Updating installed version in properties file.
dr.recovery.boot will be set to TWRP (default)
dr.initd.active will be set to false (default)
dr.ramdisk.boot will be set to false (default)
Trying to find and update the gpio-keys event node.
Found and will be using /dev/input/event5!
Trying to find and update the power key event node.
Found and will be monitoring /dev/input/event0!
Speeding up CWM backups.
mkdir: can't create directory '/sdcard1/clockworkmod/': Read-only file system
touch: /sdcard1/clockworkmod/.hidenandroidprogress: No such file or directory
Make sure firstboot goes to recovery.
mkdir: can't create directory '/cache/recovery/': Read-only file system
touch: /cache/recovery/boot: No such file or directory

=============================================
DEVICE WILL NOW TRY A DATA SAFE REBOOT!
=============================================

=============================================
Your installation has already cleaned up after
itself if you see the install.bat/install.sh exit.
=============================================

=============================================
Installation finished. Enjoy the recoveries!
=============================================

Press any key to continue . . .

Yes had rooting issue but rooted successfully using kernel: SGP312_10.5.A.0.230_kernel.ftf

So i have SuperSU and rooted using flashtool.

I tired by chaning flashfile:

SGP312_10.4.1.B.0.109_US_CA_PR_R1C.ftf

SGP312_10.5.1.A.0.283_HK-SA-SG-MY-AE-KW.ftf

SGP312_10.5.1.A.0.292_VMo UK-IE.ftf

SGP312_10.6.A.0.454_VMo US-CA-PR.ftf

SGP312_10.7.A.0.222_1273-3888_HK-SA-SG-MY-AE-KW.ftf

SGP312_10.7.A.0.222_VMo_US_CA_PR.ftf

Still no luck. Stucking permission issue.

I tired to remount using adb shell but again it's getting read-only issue after the restart.

So i want to know how can i resolve this read-only filesystem issue? I need to use TWRP to restore my backup too.

Please help me, save my tablet.

Update: Fixed.