[HD2 Android NAND Development] aortega:
Ext partitions

Hi guys, i want to drop a text about EXT partitions from a link that Tiger provided me, (i'm not an expert on EU phones which uses EXT partitions, i have a tmous) I have seen several times people asking about making EXT2, EXT3 or EXT4 partition and some knows what they are doing, but most of they don't.

When we need to create this on our EU phones, CWR creates an EXT3 partition, just because it is the format that works better with our phone's system. I know there are people that would say that EXT4 is better or some prefers that one, and other this one, etc.., but we had people with EXT2 and EXT4 partition missing data or having some other problems, just, please, let CWR make the partition it does by default and enjoy the rom, you don't really need more than EXT3. Here is the text about it, so we can understand a little bit more about this and the differences in between.

Ext2

Ext2 stands for second extended file system.

It was introduced in 1993. Developed by Rémy Card.

This was developed to overcome the limitation of the original ext file system.

Ext2 does not have journaling feature.

On flash drives, usb drives, ext2 is recommended, as it doesn’t need to do the over head of journaling.

Maximum individual file size can be from 16 GB to 2 TB

Overall ext2 file system size can be from 2 TB to 32 TB

Ext3

Ext3 stands for third extended file system.

It was introduced in 2001. Developed by Stephen Tweedie.

Starting from Linux Kernel 2.4.15 ext3 was available.

The main benefit of ext3 is that it allows journaling.

Journaling has a dedicated area in the file system, where all the changes are tracked. When the system crashes, the possibility of file system corruption is less because of journaling.

Maximum individual file size can be from 16 GB to 2 TB

Overall ext3 file system size can be from 2 TB to 32 TB

There are three types of journaling available in ext3 file system.

Journal – Metadata and content are saved in the journal.

Ordered – Only metadata is saved in the journal. Metadata are journaled only after writing the content to disk. This is the default.

Writeback – Only metadata is saved in the journal. Metadata might be journaled either before or after the content is written to the disk.

You can convert a ext2 file system to ext3 file system directly (without backup/restore).

Ext4

Ext4 stands for fourth extended file system.

It was introduced in 2008.

Starting from Linux Kernel 2.6.19 ext4 was available.

Supports huge individual file size and overall file system size.

Maximum individual file size can be from 16 GB to 16 TB

Overall maximum ext4 file system size is 1 EB (exabyte). 1 EB = 1024 PB (petabyte). 1 PB = 1024 TB (terabyte).

Directory can contain a maximum of 64,000 subdirectories (as opposed to 32,000 in ext3)

You can also mount an existing ext3 fs as ext4 fs (without having to upgrade it).

Several other new features are introduced in ext4: multiblock allocation, delayed allocation, journal checksum. fast fsck, etc. All you need to know is that these new features have improved the performance and reliability of the filesystem when compared to ext3.

In ext4, you also have the option of turning the journaling feature “off”.

Now, if you need or want to learn more about it, here is the link from where i grabbed this text:

http://www.thegeekstuff.com/2011/05/ext2-ext3-ext4/

so, thank you guys, hope this is useful to all of you, give a thank to Tiger too for his help if you feel this was, oki??. :):):)