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 :
http://leemn.wordpress.com/2011/01/28/galaxy-tab-bootloader-unlocked-by-chainfire/
Sources :
santi
January 31, 2011
Hi, this is nice.
grellanl
February 12, 2011
Good work putting your steps and results up here!
I decided I’d upgrade to ext4 (and a custom kernel to support the filesystem upgrade), so I googled for anyone that had already done so, and found your page.
The difference is well worthwhile, my Quadrant score is about 1850 now, and it’s not that the device does any one thing faster, it’s just that it doesn’t slow down and judder when doing multiple things, as used to happen.
I can’t wait to see full Gingerbread ROMs and CWM-based upgrading – this business of flashing separate partitions through Odin is unnecessarily complicated!
Gan
February 20, 2011
Can the new ROM still write chinese?
I have a Singapore set with DXJJ1 build… i wonder if it’ll take the kernel & ROM following the steps detailed here….
leemn
February 20, 2011
If you wish to write Chinese – just install the free app Google PinYin. Select this keyboard and make it active in Settings/Locale and Text
leemn
February 20, 2011
Gan : You need to check first whether your bootloader is signed or not. Download this patch, check and unsign it first before flash new kernel
http://forum.xda-developers.com/showthread.php?t=888071
Gan
February 20, 2011
aaah…. too late…. i already flashed new kernel without checking bootloader is signed or not…. now my Tab is bricked…. i’m stuck in Clockworkmod…. it says “cannot mount /sdcard”….
Help, Benny…..
Gan
February 20, 2011
mine is froyo.dxjj1, stock singtel set…
Anonymous
February 20, 2011
Gan dont panic. Now need to revive your tab. Go download rotohammer jme rom. Extract rom. Switch off tab. Go to download mode
launch odin. Connect tab to pc
flash rotohammer jme rom. Select repartition. Pit. Pda file
your tab should boot back alive
run chainfire patch n unsign bootloader
then only flash kernel
ben
April 29, 2011
hi please help! in recovery mode my tab says cant mount exy sd card! and im stuck! tried heimdall but not working. cant use odin because its not detecting my tab! please help!
Gan
February 20, 2011
Many thx Benny for your quick reply. Flashing Roto-JME-Full-v4, will I be able to retain my exisiting data on the internal SD card? My guess is not….
leemn
February 20, 2011
it will wipe clean everytime you flash a complete new full rom
http://forum.lowyat.net/topic/1731804 : this is a thread started by me – refer post 3 or 4 for tips.
Gan
February 20, 2011
oou, the chainfire u talked about to unsign bootloader is “SGT-Bootloader-Patch-v1.00.apk” , correct?
leemn
February 20, 2011
YES
leemn
February 20, 2011
http://leemn.wordpress.com/2011/01/28/galaxy-tab-bootloader-unlocked-by-chainfire/
Refer for above for explanation
Gan
February 20, 2011
Many thanks, Benny. My Tab is now back alive with Roto JME-v4 ROM.
Have run “chainfire”, only my kernel is signed, can I still proceed with the EXT4 kernel change?
leemn
February 20, 2011
No. Select PATCH IT – reset TAB and you should be OK to proceed
Gan
February 20, 2011
the “PATCH IT” is disabled, ie. cannot be clicked….
and I already flash paul’s ext4 tar file… and I’m back to like b4 getting into rotojme-v4 rom.
I suspect it’s due to I didn’t insert a compatible external microSD card…
Gan
February 21, 2011
yup, that’s it, confirmed.
It’s due to space constraint of the ext-microSD or does not have one inserted.
Below are the details:
1. Managed to revive the TAB 2nd time on Roto-JME-V4 after “repartition-flash P1000DXJJ2″ did not work. Followed your but skipped the “PRE-REQUISITES before flashing ( on Windows 7 )” part as I had already setup through KIES & I’m on Windows XP SP2.
2. Then power off after successfully booted into Roto JMEv4.
3. Insert 1GB microSD card.
4. Power ON.
5. Unmount External microSD.
6. Format External microSD. (skip if it’s empty card, need if new). Android will mount back after format.
7. Power OFF.
8. Boot into download mode (pressing vol-down + power button).
9. Use Odin V1.7 to flash “p1000-mck-r3-ext4-cwm.tar” following your guide above in this post.
10. Boot into recovery following your step above and voila! Ext4 conversion ran on its own.
11. Backed up everything -> convert to EXT4 -> restore whatever ROM that was there. I have some short video clips on this step, will share the link once I join them & upload to youtube.
12. Boot up nicely back to Roto JMEV4.
Now no doubt Roto JME V4 is TAB’s life-saver, but if let’s say I’d like to go back to one of the official ROM such as P1000DXJK2 downloaded from samfirmware.com, is it feasible?
May try this tmr using ODIN V1.7 with “Re-Partition” unchecked since I got nothing to loose now (no critical data, previously backed-up using Ti-Bkup).
Lim
February 21, 2011
Hi Benny, chanced across your blog while reading up on modding my Galaxy Tab. Enjoyed reading your posts.
Just a quick question since you converted to ETX4 kernel, do you find it stable overall, I read on forums like XDA that there are still numerous bugs. For example, everytime you boot, there is a split second of garbage display before the bootup animation.
leemn
February 21, 2011
Lim : Very stable have no issues with it. If there is any have not noticed it yet. Have been on it more than 3 weeks already. The bootup image is not an issue at all – it just appears not even a tenth of a second. Don’t think it affects anything at all. It is not garbage display – just a display of various color lines
Lim
February 21, 2011
Hi Benny, thanks for the prompt reply.
Apparently the only fix is to apply another overclock kernel patch from another developer that most likely overwrites the problem code in Modaco’s kernel.
Will hold off converting mine till this is sorted out. Quite pleased running Roto-JMG on my Tab as it is already.
leemn
February 21, 2011
It does not overwrite it when I installed Richardtrip 1.4 GHz O/C kernel on top of it.
Gan
February 21, 2011
Hi Benny,
I’m back to share what I found out about Paul O’Brien’s MCK-r3-ext4.tar and the absolute need of an external microSD card…
Perhaps it wasn’t made very clear at here / Paul’s Modaco page / Paul’s XDA post,
THAT,
an external microSD card with empty space that can support your existing ROM, Apps + Data
IS NEEDED
for Paul’s great EXT4 kernel and the included clockworkmod recovery in his .tar file to work flawlessly.
So, for those of you who are still on fence deciding whether to change to EXT4, go download and play the game “GUN BROS” from the market and you’ll definitely understand what lag due to RFS is all about! [ My TAB doesn't lag anymore playing this now that it runs Paul's EXT4 kernel ]
For those who’s taking the plunge same as Benny & I, follow my pre-requisite steps below closely if u like:
1. Make a backup of all your Apps & its Data using Titanium Backup.
2. Copy/Zip-over the TitaniumBackup folder to your home computer or anywhere safe [TAB's internal & external microSD NOT recommended!] and check the data integrity [Zip: Test Archive].
3. Now you have 2 options:
A. Get a new microSD card with enough free space that can support your “existing ROM + Apps + Data” to use as TAB’s external memory and proceed to Step 4 below.
B. Wipe / factory-reset your TAB to return to stock ROM that is with minimum space requirement and check if your existing inserted microSD card has enough free space to support. [fresh ROM usually needs ~600MB]
If formatting the external microSD will make enough room, go ahead.
4. Proceed with Benny’s guide from
“Download the EXT4 TAR file from HERE”
to
“The whole process took about 21 minutes.”
Good luck !
and enjoy the much superior EXT4 partition. I know I definitely am!
p/s: Great Thx to Benny for quick replying on my S.O.S.!
leemn
February 21, 2011
Gan : Glad to see you have did it. Actually I did mention in my blog about the need to use a external card: Perhaps you missed it. I will edit it to highlight the importance
QUOTE:
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. UNQUOTE
Gan
February 22, 2011
Hi Benny,
not sure if you know but would like to ask,
now that my TAB is running Paul’s EXT4 MCK, Roto JMEV4,
will I be able to flash to P1000DXJK2 ROM as downloaded from samfirmware ?
TQ & Cheers.
leemn
February 23, 2011
Yes you can but than your FS will revert back to RFS system. You have to redo the EXT4 conversion if you wish to use this rom
Gan
February 23, 2011
Do I need to enable .pit if I would like to do that? Sorry, noob question here…
Thanks.
Lim
February 23, 2011
Hi, having played around with the Galaxy Tab in terms of modding/ROM flashing, I find Samfirmware ROMs to be most “questionable” overall.
I speak from experience trying to flash their ROMs and this is backed up by comments on many forums like XDA Developer.
Example in point is how firmwares posted such as JM4 & KM2, which are newer Asian firmwares, are missing “dbdata.rfs”. This is crucial system file whereby Tab will hang on bootup without it. I experience this myself.
I am not sure how official & unofficial/custom ROMs differ (such as uasage/flashing procedures) but this is most strange as others have managed to get it to work by recompiling and adding the missing file from custom ROMs??? So why is this so, not sure ?
To be fair to Samfirmware, I am no expert on this and perhaps others can better explain .
Gan
February 22, 2011
ou, just like to share, Roto JMEV4 doesn’t allow USB charging while plug in to your computer while I note that my stock ROM – P1000DXJJ1 allows.
leemn
February 23, 2011
OIC never knew this as i always charge it from my IMAC or direct never through any notebook. But there is a solution to this – just install the ASUS patch and you can charge from any windows notebook. This patch successfully used by many even to charge ipad using a windows netbook. Google for it forgot the link
leemn
February 23, 2011
Gan : Every rom in samfirmware has an associated PIT file. You will notice several types of PIT files type – generally is same for certain groups. It is safer to select the correct PIT as your present partitioning system might be incompatible with it. Anyway when you select repartition you still need the PIT file to do it whether you select it or not
peterscm
February 23, 2011
Hi Benny, do u encounter stock browser having screen orientation problem? when I launch it, initially shows correct orientation. then suddenly (less than 1 second), the screen will rotate landscape and then to upside down potrait. whenI exit to Home, everything @ Home is correct. just stock browser having problem. Any solution? I even did a calibration but the issue still there.
leemn
February 23, 2011
Sorry no idea. I never use stock browser i remove it since day one. I use dolphin hd – suggest you try it it. I find it great since started using it on nexus, galaxy s and dell streak
Lim
February 24, 2011
Hi, do check out these links:
http://forum.xda-developers.com/showthread.php?t=925760&page=2 (Original thread)
http://forum.xda-developers.com/showpost.php?p=10834234&postcount=12 (Post #12)
Basically this is one of the bugs with Modaco kernel. As you can read up on the XDA forums, others have experienced it too.
But Benny has recommended other browsers, which is ideal as the stock browser on Galaxy Tab has been criticised widely for lag.
Dee
May 10, 2011
BENNY… man i dont know you… but this tutorial was by far the best detailed tut ive read. thank you. i just finished converting to ext4. god bless..
Anonymous
November 11, 2011
Did all the steps as described, now my tab is stuck on the Galaxy Logo, won’t boot except in recovery … thank you very much, you owe me a TAB! … I hate you