Samsung Galaxy S3 T-Mobile SGH-T999 (d2tmo)

[mw-merickso]

Looking to repartition Samsung S3 (SGH-T999, T-Mobile) to make /system larger such that it can hold new 7.1.1-based android and gapps. (Current 1.5G for system is insufficient.) Will be using 'wipe' options as I'm not expecting to try and preserve anything, although saving the current PIT to revert to stock might be nice if necessary.

Attached is the repit dump log. Other requested information:

your exact device and device codename.
TMobile, Samsung Galaxy S3 (SGH-T999) (d2tmo)

your recovery (version? official? if not where did you get it?).
Team Win Recovery Project: 3.0.2-0

your kernel.
Android 7.1.1
Kernel: 3.4.112-Lineage-g729643e
Build number: lineage_d2tmo-userdebug 7.1.1 NMF26V 49de5f6e60

your rom.
LineageOS 14.1 (lineage-14.1-20170206-nightly-d2tmo-signed)

is your device running the stock partition layout or is it already modified?
stock

Thank you for your efforts!

repit-dump.log.txt

[Lanchon]

thank you!

i'm currently travelling abroad, so this might take time. sorry :(

[mw-merickso]

Perhaps you could weigh in on a more direct approach using parted.

1. I tried using parted -lm /dev/block/mmcblk0 > backup_parttab.parted but it did not give any output. Do you know how to back up the current partition table?
2. my repit dump had warnings about the GPT backup not being at end of disk. is it risky to let parted fix that?
3. my GPT has /system right next to /userdata. It feels like using parted directly to shrink "up" the userdata and then extend up the system partition to fill the newly created space wouldn't be too risky.

I've done things like dual boot disks and various repartitioning schemes on disks for finer-grained backups using gparted on Linux, but have no experience with Android. There seem to be all sorts of crazy lockdowns with phones--locked GPTs!?!--so don't feel like I can properly gauge the risks.

[Lanchon]

i dont recommend that you increase system.

more info here: #56

[Lanchon]

here is a test build for your device

1. download and EXTRACT this zip file:
   EXTRACT-THIS-ZIP-(d2-test).zip
2. READ REPIT INSTRUCTIONS.
3. if you flash as-is, you will gain 0.8 GB in /data taken from /cache. this should be quick and safe.
4. if you RESIZE /SYSTEM and NOT WIPE /DATA AT THE SAME TIME USING REPIT, the operation will take a VERY LONG WHILE. this is because the huge data partition must be moved around in the disk.
5. resizing /system requires moving /data. if this operation is interrupted, you WILL loose your data. READ THE REPIT INSTRUCTIONS CAREFULLY BEFORE USING.

thanks!

[Lanchon]

please note that there is a risk involved in trying this. some devices have signed partition tables and will refuse to boot with a modified partition table. in this case, the device would be hard-bricked. typically this protection showed up on later devices (you device is old), and this is the reason ive mostly stopped work on REPIT. i would expect you are not affected, but there is no way to know.

[Lanchon]

you can use the strings command on an image of the bootloader partition to try get hints regarding GPT signatures. read about it in the GPT signing issues that are open here.