[Thunderbolt General] snicklet:
Have you ever installed a ROM that AUTOMATICALLY wiped your data when you installed it? Some ROM's have commands in their updater scripts that will AUTOMATICALLY wipe your data during the ROMs install process regardless if you chose not to wipe data before the install. This was frustrating to me because I did not want to have to go through the process of resetting up my device when I was only updating to the current version of the ROM I already had on my device.

It is always better to wipe completely before installing a new ROM, however there may be instances when you do not want to do that (i.e. upgrading from ROM version 1.1 to version 1.2, etc.). I recommend doing a full wipe when installing a new ROM however, I like to have the option to not do a full wipe and preserve my data and my system setup and not have the ROM automatically wipe my data.

If my ROM runs fine without wiping data then I like the convenience of not having to re-install all of my apps and system settings. If I find that the ROM is not behaving correctly after updating then I will go back and do a fresh install with a full wipe.

So if you have a ROM that AUTOMATICALLY wipes your data then this is how to modify the ROM so that it will not automatically wipe your data upon installing. It is very easy to do. Follow these instructions:

Navigate to the directory where your ROM is saved on your computer.

Open the ROM zip file with a zip application of your choice.

Navigate to the "META-INF>com>google>android" folder.

Extract the "updater-script" file.

Open this file with the Notepad application in Windows.

Locate this line in the text *format("ext3", "EMMC", "/dev/block/mmcblk0p26");*. It is usually somewhat near the beginning of all of the text in file.

Delete that line (note: the line will not have the * symbols before and after so just delete the line in between *'s)

Save the file but do not choose "Save as". Make note of the directory where the file was saved.

If your zip application does not ask to save the edited file automatically into the ROM zip file then re-add that file back into the ROM zip file in the original directory/folder where the file existed in the ROM zip file.

Copy the ROM zip file to your phone SD card.

Boot into recovery and install the ROM zip without manually wiping data.

Do not remove any other text lines or text characters from this file other than what is in between the *'s from the above instructions. There are no spaces in between any of the commands in the updater-script so keep the same character formatting in the file. Also, use Notepad in Windows (or a text editor in Mac; I do not know what that application is called on a Mac) for editing this file and do not use a word processing application (such as Word). Word processing applications can sometimes add hidden formatting in the text that you do not want.

This is for use with custom ROM's for the Thunderbolt. I do not know if this will work for other devices. Always make a backup before using this mod/change.

This mod/change only prevents the ROM itself from AUTOMATICALLY formatting and wiping your data upon installing. It does nothing else other than that. If the ROM itself does not AUTOMATICALLY wipe data during the install process then there is no need to use this. I have tested this successfully multiple times without issue.

The usual disclaimer applies to making this or any other modification to your device. I am not responsible for any damage this may cause to your device. Use at your own risk. However, if you made a backup then you should be fine.

I have searched the internet and the forums and did not find any instructions on how to do this so I made this post. If something like this has been posted before I apologize for cluttering the forum. Also, if I posted in the wrong forum I also apologize.

Hope this helps anyone who has this issue.:)