What's missing in Btrfs

So, after being completely betrayed[1] by Ext4 not once, but twice, I decided to evaluate my FS options for /home .

• FAT* are not an option, neither is NTFS.
• Ext2 is primitive and HFS/HFS+ is just not Linux.
• JFS is nice, but (atleast parted) doesn't support grow/shrink.
• I've used XFS before, and found it to be more reliable than Ext4. However, deleting dirs with thousands of small files is too slow (a common operation when compiling)
• ZFS would've been an option if my earlier experiences with ZFS-FUSE weren't so horrid.
• Did not even consider NILFS. It's too new, and I don't know much about it.

It ended up being a choice between the reliable Ext3, or the new-fangled Btrfs. Why Btrfs? Because I've been using it as my Gentoo Distfiles and Portage tmpdir since v0.16, and found it to be the /most/ resilient to power failures of all my partitions.

I ended up selecting Ext3 for /home, but let's see why.

What's missing in Btrfs:

1. Growing the filesystem to the "left" of the partition. The error message when you try this is cryptic (common in btrfs-progs). However, since for other FSes this essentially involves "move to left and grow to right", I suppose the "move" part is what's missing in btrfsctl.
2. Pathetic ENOSPC handling. It either throws an ENOSPC at around 75% or when the metadata space fills up. Not sure which, but it's supposedly fixed for 2.6.32.
3. Volumes once created cannot be deleted. Again, fixed in 2.6.32.
4. Parted doesn't support editing/creating Btrfs partitions. Support for detecting it was proposed recently; but, I still don't see it in either "master" or "next". This is not a Btrfs problem, but certainly affects whether I'd use it.
5. There were other minor irritants (with btrfs-progs, mostly), but those will go away with time

Ext3 might have bad performance (especially w.r.t fsync), but atleast it's more reliable. In conclusion, I'll use Ext3 in data=ordered mode for /home till 2.6.33 is out; and then I'll convert my Ext3 partition to Btrfs and forever be happy :}

1. betrayed == sending everything into /lost+found after a forced fsck due to an earlier fsck after a power failure

I don't understand this

And the fun part is, that I can't understand it. Why? Because even though I'm in college, I can't read or understand Physics papers. The learning curve is too steep.

Learning curve for physics too steep? Just pick up a book about it and read it!

Sure, and to understand the physics involved from the basics, I must learn the math involved. And once I've gone through 3 books for the math, I'd still not be able to understand peer-reviewed physics papers.

What's left? What more do you need to know?

To dive into a peer-reviewed paper, I need to be familiar with the language and syntax that they use. It's almost unreadable to a newcomer to the field. Is it just this paper or does every paper use such convoluted language and bury the facts in irrelevant claims, fancy language and dramatic bold text?

If I somehow get used to that stuff, I need to be familiar every paper of the 5 kazillion or so that it references. Especially so when it references other papers by the same author.

Bah. Anyway, I was trying to read some of the papers published by the people guy at Black Light Power. To see for myself what kind of credence to associate with his claims.

And they're just impossible to read.

I do not like hand-waving, and I do not like pretty pictures or videos. I would like my questions to be answered, or given the means to answer them myself. Papers are supposed to be a way to do that, and I can't. So I don't know what to make of his extraordinary claims.

In case you were wondering what his claims were, he's just about claiming that 40 years of QM is inaccurate because they cannot reconcile with some of his experimental observations (which have been published in peer-reviewed papers, not that I trust anything unless I can see the arguments for myself). Now, this would be something revolutionary, but there's too much such stuff going around, and it's difficult to differentiate the physicists from the crackpots.

All in all, I don't have a clue. He's right that people have a hard time getting away from their dearest theories, and I have been embarrassed by the fact that QM is one thing that no one learns, but rather "Accepts" in school and through college since the Math involved isn't taught at that level.

But really, the only way to challenge something as widely-accepted as HUP, you need a mountain of evidence (Occam's Razor and all that).

Breaking the monotony

Oh, HAI

I has other interests too !!!



And now, for the complimentary my life is as screwed up (if not more) than yours link!



This post brought to you by the people complaining of extreme geekiness in this blog
Yes, I know I cheated, but I'm in a hurry here :p

GDM 2.24 aka SMB (Shoot Me Bloody)

That's the name of my proposed WorkOut for FOSS.IN/2008.

What is it about?
It's about getting GDM 2.24 in good enough shape to be considered for adoption by Ubuntu, Gentoo, Mandriva, Debian, *BSD; and not just Fedora and Foresight.

What's wrong with GDM 2.24?
Strictly speaking, there's nothing *wrong* with it. It works flawlessly on my system (except for the daemonisation bug/regression, which I had to patch up manually). I've been using it as my primary display manager since 2.23.1, and it has improved to the point of bug-free-ness.

However, there are reasons why most distros are shipping the older 2.20* series GDM instead. The aim of this WorkOut is to make inroads into fixing those problems.

That's all fine, but what *exactly* is wrong with GDM 2.24?
Oh, right. I should impose a hand-waving embargo on myself ;p

History: Sometime around the GNOME 2.18 release cycle, the GDM developers decided that it was high-time someone fixed all the problems with GDM and rewrote it from scratch. For this reason, a rewrite of GDM was started; aiming for the 2.22 release cycle.

However, during 2.22 cycle, GDM 2.20 was shipped due to several regressions. When GDM 2.24 was proposed, it caused intense debates involving the release team. However, it was included since the feature regressions were deemed minor enough.

Some of the regressions are listed below:

• Lack of Themeing support: The architecture of the new GDM is very different from that of the old GDM. And hence, there is no way to "port" the older themes to the newer GDM, and there is currently no inbuilt support for themeing either.
• No `gdmsetup`: The older gdmsetup had several security bugs, and hence was not ported to the new GDM. The configuration file is still the same however, so this is not a really large regression since there's no theming support anyway.
• No XDMCP Chooser in the login screen: This is quite self-explanatory
• No support for timed-logins: This is being worked on actively in-trunk
• No support for backends other than PAM: This means that distributions like Slackware, *BSD, etc cannot use GDM 2.24

The aim of this WorkOut is to fix the above listed regressions, and some of the other regression bugs, TODOs, Visual Glitches, etc. And maybe even add some new features ;)

Details about the How, and When will be posted soon. Stay tuned!

~Nirbheek, hoping to see you during the discussions and @foss.in :)

An important announcement

We interrupt your regular lazy-webbing to make this two important announcements:

A) AutotuA 0.0.1 released! Try it out and report bugs (if you can't follow the instructions in the link given, your services will be required when 0.0.2 is released :)

B) IMO, the two best distros in this world are:

1. Foresight Linux
   • Ken Vandine (one of many) is effing awesome
2. Gentoo
   • The GNOME Team
   • Brent Baude (ranger): master-of-the-PPC-arch
   • Donnie Berkholz (dberkholz): X11, Council, and Desktop Team Emperor
   • Raúl Porcel (armin76): generic bitch; maintains half the arches and Firefox
   • Robin H. Johnson (robbat2): Infra demi-god
   • Zac Medico (zmedico): Portage demi-god

All these people are just too awesome (and too overworked) for words. If I hadn't got myself deep into Gentoo (which led to SoC too), I would've gone to Foresight :)

~Nirbheek,
Who has high hopes for AutotuA, and also hopes the best of Foresight and conary can be brought to Gentoo.

PS: Donnie, congrats once again! ;)