Ubuntu 9.04 does not use ext4 by default
There seems to be a significant misconception around Ubuntu 9.04, that it uses the (comparatively new) ext4 filesystem by default. It doesn’t. Ubuntu 9.04 still uses the tried-and-true ext3 filesystem by default. If you install Ubuntu 9.04 and use automatic partitioning, you will get ext3, which we consider to be the most stable option at this time.
ext4 is available as an option in the manual partitioning screen for people who wish to try out the latest stuff. There are some known bugs which affect this configuration, though, and filesystem bugs generally carry the risk of lost data, so this is not for the faint of heart.
A Linux Weekly News article included an error (now corrected) in this regard, and even our own Ubuntu Weekly Newsletter reprinted a BeginLinux.com article which implies that 9.04 carries the risks of ext4.
We included the manual ext4 option for people who want to help test this new technology, to help its developers isolate and fix any remaining bugs so that it can become the new standard for Linux and the default for Ubuntu. Many people are interested in it, have opted to try it, and written about the experience (which is probably how the misconception started).
In short, don’t panic. Ubuntu 9.04 isn’t any more likely to eat your data than any previous version.
We'll see | Matt Zimmerman 
Could you also tell us what those bugs with ext4 are ?
What are the risks?
Thanks,
sam
May 1, 2009 at 13:47
Why put the Ext4 support as an highlight in this release then? It’s like showing a candy to a kid and saying “No, don’t touch this”.
Evildead
May 1, 2009 at 14:40
We included it because many people are willing to accept the tradeoffs, because they’re interested in trying out the latest technology.
ext4 wasn’t mentioned in the press release or release announcement, though we did include an item in the technical overview at http://www.ubuntu.com/getubuntu/releasenotes/904overview#Ext4%20filesystem%20support
The text there provides a pretty clear explanation of the risks.
mdz
May 1, 2009 at 16:52
It’s completely understandable, it’s a new technology, its put there mainly for those who like to be a bit more “bleeding edge”. Tho Intrepid and Jaunty ext3 are defaulted to size 256 inodes while before they used to be 128. It’s pretty much installed following the ext4 standards.
André Oliveira
May 1, 2009 at 14:51
so the bug still exists? I thought it has been sorted out. I run ext4 now and the perceived speed increase is around 100%! Start Up time seems halfed, overall responsiveness of the system feels much better…loving it so far, no data lost either (hopefully)!
Lorenz
May 1, 2009 at 16:02
Lorenz:
The patch for the most common problem was backported. There are still other possible issues in existence.
I’m using ext4 for / and keeping /home on ext3. And I carry around a live cd in case ext4 eats itself :)
Mackenzie
May 1, 2009 at 18:35
Thanks for the info Mackenzie, I have to confess, I didn’t inform myself very well then, I thought it’s free of bigger bugs. But it’s ok, I have my important documents on Dropbox and the movies/music I back up regularly to an external HD.
Lorenz
May 1, 2009 at 19:02
[…] I wonder if btrfs will overrun ext4 before it’s even widely deployed. “Ubuntu 9.04 does not use ext4 by default” https://mdzlog.alcor.net/2009/05/01/ub… […]
IRC: #boycottnovell @ FreeNode: May 1st, 2009 - Part 2 | Boycott Novell
May 2, 2009 at 07:08
Just for the historical record (and because this post still gets traffic), Ubuntu 9.10 will ship with ext4 by default. This is already the case in the beta released last week.
Matt Zimmerman
October 5, 2009 at 21:00
Good job! It may be helpful in the process of studying ubuntu so I’ve scrape it using scrapebook(firefox addon). Can you recommend any books about ubuntu for me? yeah, I am a noob of ubuntu. :D thanks in advance!
zorph33
January 11, 2010 at 09:26