As devices get newer and more powerful, the software that comes with them gets bigger and more complex. In the old days, ROMs were often smaller than 100MB. Now, on the newest devices, the stock ROM can be over 1 GB in size. There are some potential problems with this. Uploading a ROM can take longer, downloading a ROM can take longer, and storing ROMs on your device can take up a lot of space. Now, there is a tutorial available to help cut back on those file sizes.
XDA Elite Recognized Developer and TV Producer AdamOutler wrote a tutorial to help decrease the size of stock tar ROMs that users can flash via Odin3 v3 and higher. As Adam explains:
I’ve been working with this for a bit and tonight I found that Odin will accept tar.md5.gz files. This is important for GNote2 users as the stock ROM is 1.2Gigs! You can get an extra 10-40% compression and 100% gaurantee that the files arrive to your users computer in the condition that you packaged them using this method. I have not found a guide on using the gz format so I thought I would write one up.
This can be quite useful because if you like to keep a stock tar around in case of emergencies, following his guide can make the file smaller and more manageable for those with limited storage. For developers who upload tars frequently, it can shorten upload times, as well as lower download times for the end user.
There are a few things to keep in mind. Once the tar.md5.gz is run through Odin, it loses the .gz and is extracted into a standard tar file again. This results in a full sized Odin ROM. It’s not really an issue, but it is something to keep in mind. Adam also gives an important warning for Verizon Galaxy Note 2 owners to be cautious about flashing after an IROM unlock:
Note to Verizon GNote2 users: Stay away from using Odin after IROM unlock as flashing a package intended for another device will perma-lock your device into another carrier’s bootloaders. Especially stay away from GS3 as the displays are not compatible.
In addition to the compression tutorial, AdamOutler has also updated his Hidden Menu application. It now includes an IMEI restore tutorial adapted from XDA Senior Member <:GeeK:> to work on the Verizon Galaxy Note 2. The tutorial will help with two things: backing up and restoring the NV items (IMEI, IMSI, and more).