include ext4

Jason Newton nevion at
Wed Sep 24 04:04:34 BST 2008

Theodore Tso wrote:
> As long as people are appropriately warned about not using it on
> production servers just yet, I have no problem.  Fedora 9 shipped it
> although you had to give something like "yes-i-know-ext4-is-a-
> development-filesystem" or some such on the boot line.  I believe
> Fedora 10 is going to be shipping ext4 fully enabled, and I am working
> with a particular enterprise distribution to release ext4 in preview
> form in an upcoming service pack.  Which would be another way of
> saying that yes, we would be quite comfortable.
> I might be a little worried if you were talking about enabling it for
> Intrepid, mainly because the ext4 patch set for 2.6.26 is still pretty
> large, and I'd prefer not to have to do a lot of patch backporting.
> You're not thinking about enabling it for Intrepid, are you?  You're
> pretty late in feature freeze by now, and there were was a rather
> large number of ext4-related bug fixes since e2fsprogs 1.41.0.  (Most
> are in e2fsprogs 1.41.1 and there will be an e2fsprogs 1.41.2
> relatively soon.)  And if you didn't include the 2.6.26-ext4-7
> patchset in the intrepid kernel, the one thing I would *strongly*
> recommend doing at the very least would be to patch ext4 to make
> nodelalloc the default mount option.  (Nearly all of the bug fixes in
> 2.6.26-ext4-7 and since then have been delayed allocation-related, for
> example in disk full situations.)
> So are we talking about enabling it for Intrepid or Intrepid+1?
>        	  	  		    	- Ted
Hello again,
Just to clarify, intrepid is currently based on 2.6.27, though what 
subrelease/rc I don't know.   It is using e2fsprogs 1.41.0 though but 
perhaps intrepid will be willing to adopt 1.41.1 before everything is 
frozen if 1.41.2 is out by then.  At the moment I would hope to enable 
this for Intrepid, though if it didn't make it by Intrepid+1, that would 
be quite disappointing.  And since the entire context was not included, 
I also mentioned in previous emails that installing onto ext4 (=root) 
not be fully supported, especially by default, just that the kernel has 
the fs enabled for general usage as ubuntu already supports a plethora 
of other options and ext4 already has built in barriers to make sure 
only the prepared use it.  Fedora's setup with anaconda and its default 
modules enables just this with ext4 kernel cmdline flag (previously 
iamanext4developer in 9)  enabling a root install in anaconda but 
regardless, the kernels all come with ext4dev.ko.  Similar behavior of 
intrepid would also be nice, but let me be clear that this is far beyond 
what I expect or want intrepid to have.  I just think Intrepid should 
have the ability to be able to read and write to a ext4 filesystem 
without jumping through a bunch of hoops since it seems its got the 
right environment for it right now.

So does the 2.6.27 based kernel make Intrepid a plausible environment 
for general, non-mission-critical ext4 usage?
Would Intrepid consider shipping with newer e2fsprogs 1.41.1?  I realize 
its late in the game, but things seem ready enough.  Additionally, it's 
still a day before beta :-).

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