Galaxy TAB : Changing file system to EXT4 and upgrade to Modaco Rom beta1

Posted on January 27, 2011

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Most Android devices currently use YAFFS, a lightweight filesystem that is optimized for flash storage .  The problem with YAFFS  is that it is single-threaded and  according to Google developer Ted Tso, it would likely “have been a bottleneck on dual-core systems.” EXT4 a much superior file system was used in the latest Google Nexus S. Tim Bray of Android Developers Blog has said starting with Nexus S and Gingerbread O/S , this change has bring a big boost in input and output file operations, and explains some of the amazing speed improvements seen on the Nexus S.

Samsung uses its proprietary  RFS  (Robust FAT File System) for its latest Galaxy Tab which is  similar to its smartphone the Galaxy S. Most owners of the Galaxy S has complained about the lag of the O/S . Lag Fix solutions ( such as Voodoo and OCLF ) based on a partial change to EXT 4 file system was later developed by hackers  to improve the SGS performance. On my previous Galaxy S, I noted a great  jump in Quadrant score of 1250 to 2025 using the Vooodoo lag fix.  Compared to the Galaxy S, I find the Galaxy Tab lag was minimal and is not so obvious

Ext4 is the evolution of the most used Linux filesystem, Ext3. In many ways, Ext4 is a vast  improvement over Ext3 than Ext3 was over Ext2. Ext3 was mostly about adding journaling to Ext2, but Ext4 modifies important data structures of the filesystem such as the ones destined to store the file data. The result is a filesystem with an improved design, better performance, reliability and features. Rami Taibah , a Linux specialist and founder of Linuxologist.com has explained it very well in layman’s terms at:
http://linuxologist.com/1general/ext4-filesystem-explained-in-plain-english/

So when I read that Paul O’Brien of MOdaco has worked on a new kernel for the Galaxy Tab based on EXT4 I was most interested. Following his work closely, I finally took the plunge today and  upgraded my Galaxy TAB from its RFS system to EXT4  using Pauls’ R3 version.

I downloaded the 6.8 MB  zip file and  use Odin 1.7 to flash it. The Odin process took 8 secs. The TAB restarted  and took about 20 minutes converting the file system and finally rebooted up within 25 seconds. To be doubly sure, I use another 16GB micro SD card which has no data to avoid any space lacking issue during the backup process of data while the file system changes was in progress – I’d suggest you have about 4 GB free space . About 1 GB data will be written to the external micro SD card.

These are the steps I took :

  • Download the EXT4 TAR file from  HERE
  • Launch Odin 1.7 , in PDA select the TAR file ( do not select the ‘repartition’ option)
  • Odin completed,  the TAB reset and freeze on TAB logo – is a normal condition . I switch it off ( hold down power button for 5 secs )
  • Go to Recovery Mode ( Press down VolumeUp button and switch on TAB )
  • TAB reset and  perform the EXT4 conversion ; you can see all the conversion progress on screen
  • Once completed, the TAB Reboot.

The whole process took about 21 minutes. I noticed all my data was intact with this kernel change. ClockworkMOD was installed in the process of changing the kernel. I did a backup immediately using the ClockworkMOD.

I continue to upgrade the TAB further by flashing Paul’s Modaco Custom Rom Beta1 which was just released on 26 Jan. This process is very simple.

I downloaded and copied the rom zip file into the root of the micro-SD card. Switch off the TAB. Go to Recovery mode ( Press down Vol Up and press Power switch ). TAB bootup in recovery mode. Using the Vol keys I navigate through the menus t o select zip file and update. The update just took about 5 seconds, then TAB restarted within 3 minutes with the new rom. The rom flash has deleted all my data in memory but all the data in the internal SD card remains.

Thde change in the file system to EXT4 has boost the original Quadrant score from 1072 to 1781 . Very impressive.

BEFORE : Roto’s  XXJME , AFTER : Paul’s XWJMF

BEFORE : Quadrant 1072 , AFTER : Quadrant 1781


WARNING : Please check whether your bootloader is signed or unsigned before you flash the kernel. Download the PATCH file from:

http://forum.xda-developers.com/showthread.php?t=888071

Launch the app and check status; PATCH it if necessary to unsigned it. Then only proceed to flash kernel. More explanation about this patch file at :

https://leemn.wordpress.com/2011/01/28/galaxy-tab-bootloader-unlocked-by-chainfire/

 

Sources :

KERNEL : http://android.modaco.com/content/samsung-galaxy-tab-tab-modaco-com/330378/26-jan-r3-modaco-custom-kernel-for-the-samsung-galaxy-tab/

ROM : http://android.modaco.com/content/samsung-galaxy-tab-tab-modaco-com/330489/26-jan-beta-1-modaco-custom-rom-for-the-samsung-galaxy-tab/