Ext3 and Ext4: Which file system to install?

[Sef]

Update: Ext4 is the default file system on Karmic Koala and beyond.

Disclaimer:- This thread only issues the use of Ext4 on Ubuntu Jaunty(9.04) and does not apply to earlier releases where Ext4 may not have been available as an option due to Ext4 not having been stable.

As you may have noticed, you now have the option of installing Ext4 through Ubuntu Jaunty. Ext4 is quite a big update from Ext3 but it still is only incremental and is backwards-compatible with Ext3, so it is very stable, however a few issues about the filesystem have recently sprung up that may require you to be a little careful when using this filesystem.

Reasons to stick to Ext3:-

1) Ext3 is the default file system for *buntus.

2) It is very stable, so no worries about losing your data due to crashes.

3) The one that is recommended to be on your work stations.


The issues with Ext4:-

1) There have been reports of crashes having corrupted configuration files and sometimes more with Ext4 in use.

2) This has been addressed in kernel 2.6.30, however it will not hit Ubuntu Jaunty, but Ubuntu Karmic.

3) 9.04 Release Notes: Other Known Issues for more detail.

Therefore, while Ext4 is really good, it still does need a few bugs to be ironed out, but all in all, it is quite stable for the average desktop user, just as long as you take regular backups, as you would when using any file system.

And just one more thing, Ext4 is not to be blamed completely, part of the problem stems from programs which fail to adhere to the standard regarding I/O on disk.

More information regarding this matter can be obtained here:
Theodore Tso's(One of Ext4's main developers) blog post regarding this issue:-
http://thunk.org/tytso/blog/2009/03/...-file-problem/

Article (29 May 2009): The Ext4 File Linux File System by Dr. Oliver Diedrich

(Thank you to PmDematagoda and bhodi.zazan for helping me improve this thread.)

[akrep55tr]

Thank you very much. This was a big question in my mind.

[Demonizer]

Ext4 cant be THAT bad .

[porchrat]

OK that is not great news, I thought the bugs had been ironed out, looks like I'm going to have to use ext3 in my new jaunty jackalope download

I had no idea there were so many issues, thanks for info Sef.

[jcostom]

OK that is not great news, I thought the bugs had been ironed out, looks like I'm going to have to use ext3 in my new jaunty jackalope download

I had no idea there were so many issues, thanks for info Sef.

You could always use JFS.. Fast & stable...

[psychok9]

I'm using Jaunty from the Alpha 5 version on Ext4 fs.
Some weeks ago, I've lost some files after a blackout (amule configuration and corruption of some files temp/part).
I've finding new .30 kernel... and I found here: http://kernel.ubuntu.com/~kernel-ppa/mainline/.
After a correct installation, I get a error: modprobe: FATAL: Could not load /lib/modules/2.6.etc/custom/modules.dep, no such file or directory...

Solution or other kernel/solution? I need a fixed kernel for Ext4 problems (I can't afford UPS).

Thank you!

p.s. nodelalloc can fix the problem, but the framentation of files can get worse a lot.

[bacardiandwatermelon]

You could always use JFS.. Fast & stable...

I've been using JFS since Intrepid, had no issues. Doesn't do any start up scans every 30 boots either. Only had one instance when I wished that the JFS file system could be read from within XP..

[jumbofishmeat]

I've heard reports of data loss and corruption. It's not quite as refined as it needs to be yet.

[Sef]

I've heard reports of data loss and corruption. It's not quite as refined as it needs to be yet.

Nothing new there. It was mentioned on the first post. Which is why it is not advised for computers that are need stability.

[Arup]

Running ext4 since day one of Jaunty release, not a single glitch so far on my 1 and 2 TB drives. I do have a UPS so there is no chance of dirty shutdown.