Re: [PATCH][2/2] SquashFS

[Pavel Machek <pavel@suse.cz>]

Hi!

> >>>Also, this filesystem seems to do the same thing as cramfs.  We'd need to
> >>>understand in some detail what advantages squashfs has over cramfs to
> >>>justify merging it.  Again, that is something which is appropriate to the
> >>>changelog for patch 1/1.
> >>
> >>Well, probably Phillip can answer this better than me, but the main 
> >>differences that affect end users (and that is why we are using SquashFS 
> >>right now) are:
> >>                         CRAMFS          SquashFS
> >>
> >>Max File Size               16Mb               4Gb
> >>Max Filesystem Size        256Mb              4Gb?
> >
> >
> >So we are replacing severely-limited cramfs with also-limited
> >squashfs... 
> 
> I think that's rather unfair, Squashfs is significantly better than 
> cramfs.  The main aim of Squashfs has been to achieve the best 

Yes, it *is* rather unfair. Sorry about that. But having 2 different
limited compressed filesystems in kernel does not seem good to me.

> compression (using zlib of course) of any filesystem under Linux - which 
> it does, while also being the fastest.  Moving beyond the 4Gb limit has 
> been a goal, but it has been a secondary goal.  For most applications 
> 4Gb compressed (this equates to 8Gb or more of uncompressed data in most 
> usual cases) is ok.

Okay, having limit on 4GB compressed is slightly better (and should
mean that SquashFS would actually be usefull to me).

> >For live DVDs etc 4Gb filesystem size limit will hurt for
> >sure, and 4Gb file size limit will hurt, too. Can those be fixed?
> 
> Almost everything can be fixed given enough time and money. 
> Unfortunately for Squashfs, I don't have much of either.  I'm not paid 
> to work on Squashfs and so it has to be done in my free time. I'm hoping 
> to get greater than 4Gb support this year, it all depends on how much 
> free time I get.

Well, out-of-tree maintainenance takes lot of time, too, so by keeping
limited code out-of-kernel we provide quite good incentive to make
those limits go away.

Perhaps squashfs is good enough improvement over cramfs... But I'd
like those 4Gb limits to go away.
								Pavel
-- 
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!