Vanilla Kernel 2.6 Stability vs 2.4?

chromis asks: "I am a 'Linux-from-scratch' like Linux user. I maintain my system for almost 4 years that way. I'm still using kernel 2.4, and I'm a little bit afraid for updating to 2.6 because of the problems like stability issues, driver subsystem problems, etc. I once tried 2.6.0 a long time ago, but I experienced random freezes which I could not diagnose. We all know about the development model issues, and I often read complaints about current kernel development practices. Now that kernel 2.6.13 is out, I really want to ask Slashdot: if you are a vanilla 2.6 kernel user, how are your experiences with these plain kernel.org 2.6 kernels? Is it really as bad as some people claim, or is 2.6 only usable when using a distro from a large vendor like Red Hat, SuSE, etc? I really would like to upgrade to the new vanilla 2.6 kernel eventually, but I'm a little hesitant. Any advice?"

Comments

Works for me

[meowsqueak]

I use the vanilla kernels with moderately modern hardware (up to about 4 years old) and I have no stability issues whatsoever. I tend to stay within one or two versions of the bleeding edge release.

The advantages of the 2.6 kernels (udev, nptl, device driver model) outweigh the disadvantages (i.e. risk) for my situation, in my opinion.

That said, I still use linux-2.4 on my headless server, mainly because I haven't been bothered to upgrade it recently. It works fine, so I see little point in changing it.

Re:Works for me

[Aeiri]

To really answer your question, what they ... need to know is what you'e using your computer(s) for. Are the advantages of the 2.6 kernel as listed above advantages for you?

I've used a vanilla kernel 2.6 on Slackware for three different uses, my headless server, my media center PC, and my brand spanking new laptop.

All 3 have worked perfectly without freezing since 2.6.5 (I didn't start using 2.6 until 2.6.5 came out). Now they are all running on 2.6.12, and they will soon be upgraded to 2.6.13.

I'd say the organization of the configuration (make menuconfig) and the overall model the kernel is based on is much more clean and organized. I could never go back to 2.4 now.

If you really want to test out the 2.6 kernel without installing/configuring anything, download Knoppix and try it out on your computers. If it runs well, then try it yourself, if it doesn't, then just stick with 2.4.

Seems ok.

[ColaMan]

I've used various incarnations of 2.6 on my mythtv box. It's under fairly high load, with memory, video and disk intensive processes, has high PCI utilisation (2 capture cards, sometimes running at once). It runs 24/7, sometimes hot enough to get the CPU temp alarm beeping.

Number of times it's had a kernel panic over the last year? Zero. Good enough for me.

And as other posters have said, the advantages with hardware, latency patches, acpi support help too.

Re:Seems ok.

[spagetti_code]

Its not all rosy. The kernel version (2.6.11.7) used in Knoppmyth has an issue with USB hard drives - hence my extra HDDs plugged into the myth box were attached using firewire (not that its a problem).

My point is that the 2.6 kernel is not without its flaws - it depends which particular kernel version you get and which warts it has.

My advice is if it ain't broke...
Do you really *need* the hassle of the upgrade?

Gentoo 2.6.13

[Professional Slacker]

I can't speak for the vanilla kernel, but the Gentoo 2.6.13 kernel borked my system something fierce. The init process grinds to an virtual stop just after loading the kernel, it took a minute and a half to set the host name, I still haven't had the patience let it finish booting. But that's the risk of using a fresh kernel. 2.6.12 didn't give me any trouble.

Re:Gentoo 2.6.13

[rincebrain]

Seconding. Gentoo user of vanilla sources straight from kernel.org, and the gentoo sources are a lot more unstable than the vanilla sources.

I use vanilla sources regularly, and haven't experienced any problems as a result. I recommend them to all of my Linux friends, too.

Re:Gentoo 2.6.13

[thegrassyknowl]

I've heard of several issues with Gentoo kernels on Multi-processor systems.

I just remembered the exact problems I'd heard of, and it wasn't Gentoo-specific (but it only appeared on Gentoo for some strange reason)... It was a CPU freq scaling thing with AMD64 CPUS. Apparantly the latest driver is broken and when the frequency scales down in one CPU the kernel detects a loss of sync and panics, instead of realising that the CPU frequency is scaling and compensating for it.

It's fixed by disabling CPU frequency scaling. Apparantly AMD are working on a PowerNow patch for it, but that is just hear-say AFIK.

Re:very stable

[ivan256]

Doesn't the FC3 at the end of the version string mean "Fedora Core 3"?

That's not a vanilla kernel, it's a patched up kernel from RedHat.

Most importantly, read the expert documentation.

[atomic-penguin]

You will need the appropriate hotplug utilities, get them here.

The 2.6.8 kernel had an issue with CD writing (only root could do this). This has been corrected in later kernels. You may have to delv into the udev rules to get things setup the way you like. Read the fine HOWTO on writing rules for udev.

My cd-rom did not get recognized after boot unless the ide-cd module was called before udev started. There was a mixup with tty and pty in the default udev rules around the time of switch between 2.6.7 and 2.6.8 and it obliterated the 'less' and 'man' commands. How convenient is it that I can't run 'man udev.rules'?
 
I believe this has also been remedied since then. If in doubt I suggest taking the following steps.

1. wget ftp://ftp.kernel.org/pub/linux/kernel/v2.4/linux-2 .6.x.tar.bz2
2. tar jxvf linux-2.6.x.tar.bz2 && cd linux-2.6.x
3. less README
4. cd Documentation && less post-halloween-2.6.txt

 
Title of the second document is "The post-halloween document. v0.48 (aka, 2.6 - what to expect)". That should tell you everything you need to know about upgrading from 2.4.

Loving my Linux From Scratch, kernel 2.6.11.12

[qualico]

Built a Hylafax http://hylafax.org/ system on top of the latest v6.1, LFS http://linuxfromscratch.org./
Details:
3GHz Intel Pentium 4 Processor, 1Gb RAM
11,878.40 BogoMIPS Total, 250Gb Hard Drive
    GCC 3.4.3
    Samba 3.0.14a
    HylaFAX 4.2.1

Gotta say it's way ahead of expectations.
I won't touch another distro now for my mission critical.
Although, Knoppix, http://www.knoppix.org/ and Ubuntoo, http://www.ubuntulinux.org/ are great "insert CD and run" distros, for workstations.
Working with SlackWare seems effortless also, http://www.slackware.org/.

Was fortunate enough to meet the fine gent who started the LFS project: Gerard Beekmans
Highly recommended support for the project, even if it's just $5 for a beer via donations :->, http://www.linuxfromscratch.org/hints/contribute.h tml or a much needed "hints" writeup, http://www.linuxfromscratch.org/hints/.

2.6.13 is very stable

[objorkum]

I am using a plain vanilla kernel (2.6.13) on my Slackware 10.1 system, and it's very very stable. The earliest 2.6 kernels were a bit unstable for me, but since 2.6.8 or so, they have been very very stable. I notice that my self-configured 2.6.13 kernel is faster than the Slackware vanilla kernel (2.4.29). GNOME responses faster to my actions, for example.