Ext4 Filesystem Enters Experimental Kernel Tree

An anonymous reader writes "Looks like the next version of the venerable Linux 'ext' filesystem is just around the corner. Andrew Morton has added an early version of ext4 to his 2.6.19-rc1-mm1 tree, enabling Linux to support storage volumes up to 1020 petabytes in size, and to write files in 'extents,' or contiguous, reserved areas. According to an article at Linux-Watch, ext4 will be ready for production use within six to nine months, if all goes well. On the downside, the new ext4 filesystem will offer only limited backward compatibility with ext3-aware Linux kernels."

Comments

performance

[bioglaze]

How does ext4 perform when compared to, say, reiserfs 3.6 or 4? What new features there are?

Interesting in light of OpenSuSE's decision...

[Saint Aardvark]

to no longer use ReiserFS as its default FS (orig. reported on OSNews.com...don't think I've seen it here yet). I think this came out before the whole Hans Reiser affair, BTW.

SuSE contrasted the ease of upgrading ReiserFS and ExtFS versions:

ReiserFS v3 is a dead end. Hans has been pushing reiser4 for years now and declared Reiser3 in maintenance mode. Any changes that arent bug fixes are met with violent resistance. Reiser4 is not an incremental update and requires a reformat, which is unreasonable for most people.... Ext3 has a clear upgrade path. There is quite a bit of interest in the community in improving ext3, and ext4 is already under development. Like the upgrade path from ext2 to ext3, the path to ext4 is clearly defined. Existing file systems can be updated easily, and new files will be able to take advantage of the new features.

Novell Suse prefers Ext3/Ext4 over ReiserFS 3 / 4

[maggard]

Other Reiser issues aside, the SuSE folks at Novell are looking to leave the nearly unsupported reiserfs3 (in maintenance support, which isn't enough for them) and move to ext3 as their default FS. Why? They feel ext3 is a lot more mature & better/wider supported then reiserfs4, is an easier migration, and appreciate that there is a solid roadmap from ext3 to ext4.

Of course this would also be the week that (coincidentally) Andrew Morton gives reiserfs4 the green light for eventual mainline kernel inclusion.