Linked by Thom Holwerda on Sun 14th Oct 2007 14:52 UTC, submitted by Oliver
BSD and Darwin derivatives Matthew Dillon writes: "I am going to start committing bits and pieces of the HAMMER filesystem over the next two months. Note that the filesystem will not be operational until we get closer to the 2.0 release in December so these bits and pieces will not be tied into buildworld/buildkernel until then." Features: maximum size of half an exabyte, infinite snapshots, limited only by retention policy, streaming backups, asynchronous transactional support (no long fscks to check disk state). Dillon also explains why he chose not to use Sun's ZFS.
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Waste of time....
by hartvig on Mon 15th Oct 2007 05:59 UTC
hartvig
Member since:
2007-04-25

The problem ZFS has is that it is TOO redundant. You just don't need
that scale of redundancy if you intend to operate in a multi-master
replicated environment because you not only have wholely independant
(logical) copies of the filesystem, they can also all be live and online
at the same time.


I mean, he literally assumes all servers running DragonBSD will be live and replicated, thus not needing the extra redundancy built into ZFS.

What the hell has he been smoking? and then I'm not even considering the idea that it would be really REALLY nice to have a true cross OS filesystem that can be used on all *BSD, OS X and linux (then we only need ZFS for windows... anyone? ;-).

Reply Score: 3

RE: Waste of time....
by dude on Mon 15th Oct 2007 06:31 in reply to "Waste of time...."
dude Member since:
2007-09-27

One of the main goals of dfbsd is to make a OS that is highly suited for clustering. Basically, he is making a file system that is better for this environment.

As for the cross platform FS, all the operating systems i've ever seen can use FAT, and the unix-like ones have UFS covered as well.

Reply Parent Score: 2

RE[2]: Waste of time....
by Doc Pain on Mon 15th Oct 2007 18:39 in reply to "RE: Waste of time...."
Doc Pain Member since:
2006-10-08

"As for the cross platform FS, all the operating systems i've ever seen can use FAT, and the unix-like ones have UFS covered as well."

Just as a technical sidenote, I found the "tar file system" being one of the best cross platform file systems. It's not a real file system in fact, but it can utilize any formatted storage media for data interchange among all UNIXes, Linusi, and Mac OS X.

For example, if you

% fdformat -y /dev/fd0
% tar cf /dev/fd0 /etc/rc.d/*

you can transfer this archive to a completely different system using

% tar xf /dev/rfd0

These systems do not even need to have any other than their own file system (e. g. UFS, ext2) represented as a part of the kernel (or a KLD / LKM). Only the desired device drivers are needed, of course.

You can access floppies (anyone still knows them?), CDs, DVDs, PDs, all kinds of memory cards and sticks and even tapes this way. Just imagine /dev/da0, /dev/sa1, /dev/rft0 or something similar in the example above. Compression (flags z or j) can be added if required by transfer sizes exceeding media size.

One advantage is the ability to work with directory hierarchies, file attributes, user and group settings, and selective access - things FAT cannot do.

Regarding FAT, the worst solution prevails, as usual. :-)

Edited 2007-10-15 18:46

Reply Parent Score: 1

RE: Waste of time....
by yorthen on Mon 15th Oct 2007 11:08 in reply to "Waste of time...."
yorthen Member since:
2005-07-06

I mean, he literally assumes all servers running DragonBSD will be live and replicated, thus not needing the extra redundancy built into ZFS.


It really is not a bad assumption, DragonFly is a good system, but if you are really running a server there are other, better systems to use.

The whole idea with DF is to be a clustered single system image OS, anything but that is just a bonus.

Reply Parent Score: 1

RE: Waste of time....
by whartung on Mon 15th Oct 2007 17:05 in reply to "Waste of time...."
whartung Member since:
2005-07-06

I mean, he literally assumes all servers running DragonBSD will be live and replicated, thus not needing the extra redundancy built into ZFS.


Umm..of course he assumes this. That's a driving goal of the entire project. The goal isn't for a general purpose one size fits all file system. Rather it's for a a file systems designed from the ground up to works in a multi-master, shared nothing cluster environment.

That a primary reason for rejecting ZFS initially for this aspect of the project.

Reply Parent Score: 4