ext3fs in Linus' Kernel Tree

peloy writes: "According to Linus' changelog for Linux 2.4.15pre2, the long waited ext3fs, the sucessor of ext2 with jounaling capabilities, has finally made its way into the official kernel tree. I have never tried ext3fs but it looks that now that it is "blessed" by Linus I'll be upgrading my old and trusty ext2fs partitions soon."

Comments

it's really simple

[matrix0040]

well the best part about ext3 is if something goes wrong .. you can convert the system back to ext2 in a second.. just mount it as ext2;-) having said that .. i've been using ext3 for over a year now without any glitch. i had a 30G partition and lots of power failures .. so ext3 really eased my life and converting a current ext2 to ext3 is also pretty simple. no more backup of 30G of data ...

ext3 and quotas....

[weave]

I'm trying to decide whether or not to convert a production system I manage that has 16,000 user accounts connected to a 1 terabyte EMC SAN. I've done a lot of searches and turned up some troubling posts about ext3 when it comes to using it with journaling and quotas turned on.

It's like what's worse, dealing with a fscks that seems to take hours or increasing the risks of more crashes but at least you get back up faster. I can't live without quotas either. Can you imagine a student in a lab with a 10 Mbps connection to the Internet and a few hundred gigabytes of writable space? :)

It's starting to look like I can't have my cake and eat it too. :(

I'm glad Linus is blessing it. Hopefully the issues will be resolved soon. Until then, maybe redhat jumped the gun including it in their distro...

Re:What? I didn't see any musos getting eaten

[baptiste]

how this wound up in a 2.4.* kernel instead of 2.5.*, where right now it really belongs,

Heck if we can swap out the VM midstream, this is nothing :) Actually I think Linus was VERY smart to push the new VM into the kernel. Why? Because I believe he avoided a LOT of people running patched kernels until 2.5 was released. It was obvious the 2.4 VM was broken. Had he held off, folks would have realized (though probably slowly) that the new VM was better and they'd have patched it in anyway.

The same holds true for ext3. RedHat is already shipping it with RH 7.2. Its rock solid from their standpoint. So it makes sense to include it in the stable kernel. Sure, we all wish Linus had the ESP ability to have known to include these things at 2.4.0 (wait the new VM didn't exist then :) ) but given current circumstances, these are smart moves. Otherwise we'd all be patching kernels for another year to get ext3 (if we wanted it) and the new VM.

Yes, I realize patching kernels is a fact of life - I do it all the time to get XFS for my desktops and servers, but the less patches I need to worry about the better.

We can stick our noses in teh air and talk about how Linus never let big feature patches into the kernel before - well, everyone is allowed to change their mind. Besides, its not THAT huge a deal. If you're worried about stability, stick with what works. But if you need newer features for your setup, you can use a more recent stable kernel.

In the end, this ensures stuff in high demand sees production use earlier. If we waited to 2.6, you'd just be delaying it to far, not just for the new kernel development time, but also the 'I can't use 2.6.0 in a production box) so you'd wait until a later release. Just like you've waited to deploy 2.4.x production, right? :)

Things change. RIght now, I'd say for the bulk of the production systems, the smart move is to wait until Linus hands the kernel off for maintenance. Once that happens it'll see MUCH less churn. Befure we had 2 release stages... 2.x where x is odd for development, 2.even#.low# for release beta, and 2.even#.big# for stable production ready kernels I think thats a good thing. Besides its all relative - saying Linus shouldn't put x, y, z in the kernel because the last number is too high is pointless. We just need to adjust to the new release schedule!

I'm glad 2.4 has what it has. Now hopefully 2.6 will have XFS and I can run vanilla kernels again (nah - never gonna happen :) )

Re:Ugh... More FUD From Within...

[Lumpy]

as a good example..

I have 1 linux box that is only accessable via Packet radio. It is currently about 250 feet in the air and about 35 miles away running on a 386 1/2baby motherboard (tiny mobo, almost a sbc too.) I installed in 1996 for the local ham radio group. It acts as a packet repeater/packet BBS and runs off of a Solid state IDE disk drive (A whopping 20 megabytes!!!)

It runs Kernel 1.2.5 from a reallly old yggdrasil distribution.

It hasn't been touched cince and has only rebooted because of power failures.

Linux is so horribly stable that it has worked flawlessly without attention for 6 years...

I dare anyone to show me a windows/dos/Xenix install that can do the same. Would you put it in a place that makes it basically impossible to get to without hiring someone at $290.00 an hour to bring it back down to you.

History of kernel video drivers

[maynard]

Um, I was once told to (and subsequently did) install Linux on my main machine in 1996, when I was told that regardless of a bad video driver, the drivers themselves never enter protected memory space and shouldn't bring down the system. (I argued that the display drawer itself may crash, but no one seemed to agree with me).

Back then you were told right. In 1996 you were likely running a kernel 2.0 based distribution with Xfree86-3.x.x. At that time the XFree project wrote separate X servers for specific video chip set support with no integration into the kernel. Mind you, the X server still ran SUID as root, and had control of the console, so a crash might not take down the entire system (networking, disk, and VM would still be up), but the net result could be a hosed console requiring a reboot anyway.

At the time Linus was staunchly against integrating video support into the kernel as a general device driver, even though an ongoing project called GGI (General Graphics Interface) had written a proof of concept video kernel module, supporting libraries, and an X server. Their system prevented these kinds of crashes by providing an abstraction API layer for applications to access the video hardware through the kernel, just as DRI does today, instead of having individual applications responsible for writing to the hardware directly. The argument then was that no userspace application should write directly to hardware considering the potential for race conditions, security problems, etc. And since all other hardware has an API layer through to the kernel, why not video?

This concept won out, but not the GGI project. Which is too bad because they had a good idea and a working system back in '96. I'm sure there were some politics involved, maybe a project lead at GGI pissed Linus off or something. I wasn't paying enough attention at the time.

Just a note about this in comparison with NT: the idea is to abstract out video acceleration routines into a hardware independent API for programmers. In NT 4.0 (which was current at the time), Microsoft placed not a video hardware acceleration API into kernel space, but much of GDI (their windowing system API). Many people thought this was unnecessary kernel bloat and complained vociferously about it being a prime cause of NT 4.0's instability. I'm not an NT programmer, nor do I know much about it's internals, so if anyone wishes to chime up and offer a better explanation please feel free.

One last point: now that DRI provides a direct kernel interface to video hardware, it's quite possible to take down an entire system with an errant DRI kernel module. Yup -- exactly the same kind of problem that linux advocates used to sneer at NT users over. The NVIDEA GForce proprietary DRI kernel modules are a prime example of problem drivers crashing people's systems. Ironic, huh?

Cheers,
--Maynard