[Galaxy S I9000 Android Development] hardcore:
WARNING: This procedure is risky and may result in loss of data.

This is a follow up to findings made in this thread: http://xdaforums.com/showthread.php?t=819580

Many people have been asking for an ext2 lagfix. You can get something similar but (arguably) better: ext4 with no journaling. Ext4 no-journal performs as fast or faster than ext2 because of performance improvements made in ext4.

Quadrant comparison for ext4 /data-only lagfix:

ext4 scores about 1500, ext4 no-journal scores about 1650.

This should work with existing kernels that support ext4 lagfixes. It's tested on a ULFK kernel (SpeedMod).

WARNING: Turning off journaling makes your data more susceptible to getting corrupted, although the risk is small.

Disclaimer: No promises that this will work for you, or that it won't corrupt your data. Try this at your own risk.

Step 0: You start off by applying an ext4 lagfix. If you are already using an ext4 lagfix, you can skip this step.

For ULFK kernels, this is either:

- "Voodoo" ext4 /data

- No-RFS advanced ext4

After the lagfix has been successfully applied and your phone is up and running properly, then you can proceed to convert the ext4 partitions.

Step 1: Make a backup of your data, using CWM (recommended). If anything goes wrong, you can restore the backup later.

Step 2: Download the tune2fs file attached to this post (works for FROYO roms only), and copy it to /data as /data/tune2fs:

adb push tune2fs /sdcard/

adb shell

# su

# cp /sdcard/tune2fs /data/

Procedure if your kernel has ro.debuggable enabled:

Step 3: If your kernel has ro.debuggable enabled, then boot your phone into recovery mode. Then run adb in root mode:

adb root

(wait for adbd to restart)

adb shell

Copy tune2fs to the /tmp folder.

# cp /data/tune2fs /tmp/

If you don't have ro.debuggable enabled, "adb root" will give you an error. Go to Step 3A in the next section.

Step 4: Now in ADB shell, find out which partitions are ext4:

# mount | grep ext4

mount | grep ext4

/dev/block/mmcblk0p2 on /data type ext4 (rw,noatime,barrier=0,data=writeback,noauto_da_alloc)

/dev/block/stl10 on /dbdata type ext4 (rw,noatime,barrier=0,data=writeback,noauto_da_alloc)

/dev/block/stl11 on /cache type ext4 (rw,noatime,barrier=0,data=writeback,noauto_da_alloc)

In this example, the 3 partitions are:

/dev/block/mmcblk0p2 (/data)

/dev/block/stl10 (/dbdata)

/dev/block/stl11 (/cache)

Repeat Steps 5 to 9

for every partition you want to remove the journal from.

The next steps show the procedure for /dev/block/mmcblk0p2 (/data).

Step 5: Unmount the partition:

umount partition_mount_point

for example:

# umount /data

Step 6: Check if there is a journal:

# /tmp/tune2fs -l /dev/block/mmcblk0p2 | grep features

You should see something like this:

Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize

You should see "has_journal" in the features. It means this partition has a journal.

Step 7: Fsck the partition:

# e2fsck -f /dev/block/mmcblk0p2

Step 8: Remove the journal:

# /tmp/tune2fs -O ^has_journal /dev/block/mmcblk0p2

(this is a capital "O"!)

Step 9: Check if the journal was removed:

# /tmp/tune2fs -l /dev/block/mmcblk0p2 | grep features

You should see something like this:

Filesystem features: ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize

You should see "has_journal" is NOT there.

Done for this partition.

Step 10: After you've remove the journal from all the partitions you wanted to, shutdown the phone by pressing the power button.

DONE.

You only need to do this procedure once

and it'll "stick" until the next time you re-format the partition.

--------------------------------------------------

Procedure if you don't have ro.debuggable enabled:

Step 3A: If you kernel does not have ro.debuggable enabled, then you can try doing this using normal adb with su while the phone is running.

But this is much more risky.

To lower the risk, do this right after booting, wait for the Media Scan to complete.

adb shell

# su

Step 4A: Now in ADB shell, find out which partitions are ext4:

# mount | grep ext4

mount | grep ext4

/dev/block/mmcblk0p2 on /data type ext4 (rw,noatime,barrier=0,data=writeback,noauto_da_alloc)

/dev/block/stl10 on /dbdata type ext4 (rw,noatime,barrier=0,data=writeback,noauto_da_alloc)

/dev/block/stl11 on /cache type ext4 (rw,noatime,barrier=0,data=writeback,noauto_da_alloc)

In this example, the 3 partitions are:

/dev/block/mmcblk0p2 (/data)

/dev/block/stl10 (/dbdata)

/dev/block/stl11 (/cache)

Repeat Steps 5A to 8A

for every partition you want to remove the journal from.

The next steps show the procedure for /dev/block/mmcblk0p2 (/data).

Step 5A: Check if there is a journal:

# /data/tune2fs -l /dev/block/mmcblk0p2 | grep features

You should see something like this:

Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize

You should see "has_journal" in the features. It means this partition has a journal.

Step 6A: Fsck the partition:

# e2fsck -f /dev/block/mmcblk0p2

WARNING!!! Running e2fsck on a mounted filesystem may cause

SEVERE filesystem damage.

Do you really want to continue (y/n)?

Answer yes.

Step 7A: Remove the journal:

# /data/tune2fs -O ^has_journal /dev/block/mmcblk0p2

(this is a capital "O"!)

Step 8A: Check if the journal was removed:

# /data/tune2fs -l /dev/block/mmcblk0p2 | grep features

You should see something like this:

Filesystem features: ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize

You should see "has_journal" is NOT there.

Done for this partition.

Step 9A: After you've remove the journal from all the partitions you wanted to, shutdown the phone by pressing the power button. Reboot the phone and hope everything works.

DONE.

You only need to do this procedure once

and it'll "stick" until the next time you re-format the partition.