Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3

Jeff Garzik
2006-06-09T20:31:23Z

Andreas Dilger wrote:
> The other issue is that adding a new "ext4" filesystem type will cause
> userspace tools to break that assume they know something about the
> filesystem type. They will all detect the filesystem as "ext3" and try
> to mount it as such, when the required kernel filesystem is ext4. Or
> we will need to have "mkfs.ext4", "fsck.ext4", etc, for no particular
> reason.

Yes, you want those tools, and you want to call the filesystem ext4.
Otherwise you'll never break free of the existing metadata formats
(which are apparently changing over time _anyway_).

> Either a system upgrades totally to ext4 to avoid the duplication of code
> in memory (and breaks ALL backward compatibility, for no good reason), or

Correct. You must upgrade totally to ext4.

And this happens ANYWAY once extents/etc. are enabled. Its an upgrade.

Jeff