Thursday, October 29, 2009
Painless kernel mods with ELRepo
Here’s something to give a try if you’ve got a test box sitting around just begging for something to do.
First off, let me make clear that my only connection to the ELRepo yum repository is as a grateful user. ELRepo is, in the words of the main page:
a RPM repository for Enterprise Linux packages. ELRepo supports Red Hat Enterprise Linux and its derivatives (CentOS, Scientific Linux and others).
ELRepo currently focuses on hardware related packages to boost your experience with Enterprise Linux, this includes filesystem drivers, network drivers, webcams and video drivers.
During some (still inconclusive) testing of a failed firewire (IEEE1394) connection using the CentOS Plus version of the latest kernel for RHEL, I decided to give the relatively new ELRepo a try.
The packages available from the repo leverage one of the main design advantages of the Linux kernel, the fact that hardware drivers can be installed and loaded as modules without necessitating a complete recompile of the kernel. An extension of this is to use the “kABI tracking kmod” feature in RHEL to obviate the need to recompile driver modules on every kernel update (which are quite frequent, even for the very stable RHEL product). As explained in the ELRepo FAQ:
Linux drivers must be built against the kernel for which they are to be used. As most drivers are part of the kernel, this normally isn’t a problem. However, when using 3rd party drivers, the driver must be recompiled against each new kernel. This causes inconvenience for users who must rebuild the driver against each new kernel update. A kABI-tracking kmod is a kernel module (driver) that is compatible with any given kernel Application Binary Interface. A consistent kABI is a key feature of an Enterprise Linux distribution and, so long as upstream doesn’t break the kABI, a kABI-tracking kmod driver will work across all kernels for a given Enterprise Linux distribution (eg, RHEL-5, CentOS-5, Scientific Linux 5) without the need to recompile the driver for each kernel update.
In my case the commercial nvidia drivers I need to allow VMware and other applications to make the most of my add-on graphics cards are now available from ELRepo as kABI packages. The required packages for the latest CentOS 5.4 kernel are:
kmod-nvidia-185.18.36-2.el5.elrepo
nvidia-x11-drv-185.18.36-2.el5.elrepo
In addition to the nvidia card, I also chose to install the following package to IEEE1394 (Firewire) support, which I used to rely on the CentOS Plus kernel for:
kmod-ieee1394-1.0.0-3.el5.elrepo
Thus far, this hasn’t helped me to get dvgrab working with my firewire-equipped minicam any more than the CentOS Plus kernel, but I’m hopeful a little more time invested in debugging (and search bug reports) will pay off.
Friday, September 18, 2009
HP recognizes CentOS, and what's this about Karanbir having a sense of humor?
You know you’ve gone “big time” when HP creates a support pack for your distribution:
Proliant Support Pack for CentOS 5 (picked up off Karanbir Singh’s blog, Thinkability).
Also, from the CentOS lists: Karanbir has a sense of humor!
[CentOS] [Found] CentOS is dead, long live CentOS
Steven Vishoot
Thu Sep 17 18:57:20 UTC 2009* Previous message: [CentOS] [Found] CentOS is dead, long live CentOS
* Next message: [CentOS] [Found] CentOS is dead, long live CentOS
* Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]—– Original Message —-
> From: Karanbir Singh
> To: CentOS mailing list
> Sent: Wednesday, September 16, 2009 1:15:59 PM
> Subject: Re: [CentOS] [Found] CentOS is dead, long live CentOS
>
> On 09/16/2009 06:27 PM, Johnny Hughes wrote:
> > If we were having wild beer parties every week .
>
> *WHAT*!!!! beer parties ? Where ? When ? will there be food as well ?
>
> –
> Karanbir Singh
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
>huh…wait a minute Karanbir has a sense of humor? :-D
* Previous message: [CentOS] [Found] CentOS is dead, long live CentOS
* Next message: [CentOS] [Found] CentOS is dead, long live CentOS
Thursday, September 10, 2009
use Seagate;
No. It’s not a perl module. It’s a hardware brand. One that I’m going to endorse right now with absolutely no incentive of any kind from the company.
Not so much for anything they’ve done, so much as what their competitors have failed to do.
Many, many years ago one of their famous competitors started a marketing campaign that included a great warranty program. Basically the deal was that if one of their hard disk drives failed within 3 years of purchase, they’d replace it free of charge.
That policy still holds, although the warranty period has been extended to 5 years for their higher-end devices.
The one that failed the other night was made by that manufacturer. It was only 2 years old. Ironically the Seagate disk that’s been in the same box for almost 4 years now is still chugging along nicely.
While I’ll be making a warranty claim on the other manufacturer’s drive, long experience tells me that the replacement will probably last about as long as the original.
And then there’s the hassle of having to spend hours recovering my data off a bad drive.
Lesson learned.
From now on I buy only Seagate.
Thursday, August 13, 2009
External 4:3 monitor for a T61
I made a few changes to this when my original configuration gave me weird results. This kind of configuration is unfortunately an art, not a science.
This will be a quick, barebones, description of what I did to get this working.
Here’s the background:
Widescreen (6:9 aspect, 1440×900 rez) Thinkpad T61 laptop with the nvidia Quadro NVS 140M graphics subsystem.
O/S is CentOS 5.3 updated to latest (2.6.18-128.4.1.el5) kernel.
External 17” LCD monitor (4:3 aspect, 1280×1024 rez).
Here’s the setup:
Install a proven driver for the nvidia 140M card, which at the moment is 177.70.33 (Feb 2009).
Reboot machine with external monitor attached for what follows.
Fire up nvidia-settings as root and go to “X Server Display Configuration”.
Click on “Layout” for external display screen and then “Configure”button.
Select “Separate X screen” and OK.
I originally tried using “Twinview” with the “Position” set to “Clone” for the second screen, As a result I was unable to see the logon box when coming out of inactivity. In addition full screen for VMware console had made the image on the external monitor offset to the right, with a 1 inch black bar to the left of the screen. The main drawback to the “Separate X screen” configuration is that you can lose your mouse pointer to the other (inactive) screen if you push it over to the right, beyond the first screen boundary.
On “X Screen” tab, “Position” should read “Absolute”, “+0+0”.
Then click on Layout for “LEN 1440×900”, the laptop’s own screen.
Make sure settings look good (1440×900 rez, Position “”Right of”).
Press “Save to X Configuration File”. Restart X (Cntrl-Alt-Bksp).
Voila!
Wednesday, August 12, 2009
The T61 uses this nvidia driver
This evening when I got home from work I decided apply the latest kernel update to all my CentOS 5 machines, including the trusty Lenovo Thinkpad T61 I was issued by my employer. The impetus was another in a series of Enterprise Watch List e-mails detailing the vulnerabilities cured by the last couple of updates.
The new kernel package I downloaded is:
kernel-2.6.18-128.4.1.el5.centos.plus.i686.rpm
The upgrades went smoothly, including the one for my home desktop that has an nvidia 6200TC card in it. Checking the nvidia web site, I found that the latest driver was released in July. So along with the kernel upgrade I decided to install the new driver. The specific package was:
NVIDIA-Linux-x86-185.18.31-pkg1.run
After I’d upgraded all the other machines it was the Thinkpad’s turn. I installed the kernel with an “rpm -ivh” and then upgraded the related kernel packages (-headers, -devel and -doc) with an “rpm -Uvh”.
Rebooting to runlevel 3, I then installed the same video driver I’d used on the nvidia desktop. Another reboot and I had… FAIL. Just the blinking caps lock indicator and a black screen that hinted something was seriously hosed.
Going over the the nvidia support site I noted that in fact the graphics chipset on the laptop, the Quadro NVS 140M, actually didn’t have a current shipping production driver but only a beta driver released in 2007. After trying that driver all day, I decided to dig some more, and found this one (released Feb, 2009) worked as well or better:
NVIDIA-Linux-x86-177.70.33-pkg1.run
Like the other drivers, this was installed while in runlevel 3.
Later on, after docking the laptop so I could use my external 17” LCD panel, I found that I was able to open up the VMware web console full screen — something that hadn’t worked with the previous version of the 185.18 driver I’d been using for the last couple of weeks (more on getting the T61 to work with a 4:3 external LCD in a post to come).