Red Hat Inc. rules the "enterprise" Linux market with their Red Hat Enterprise Linux (RHEL) product line. Novell Inc. (now owned by The Attachmate Group) is second with their SUSE Enterprise Linux product line. To the best of my knowledge, there aren't any free SUSE Enterprise Linux clones but there are a number of free RHEL clones. CentOS is the most well known RHEL clone but with the seeming unending delay of the 6.0 release (July 11th is my guess), CentOS has received quite a bit of criticism leading some users to investigate alternatives. As a result, Scientific Linux is getting a lot of long overdue attention given the fact that it too is a solid enterprise clone... that has been around for a long time... that has a lot of support behind it.
MontanaLinux is proud to present an interview that was conducted via email with Troy Dawson who is a long-time Fermilab employee and Scientific Linux developer.
About Troy Dawson
Montana Linux: Please tell us about yourself... as much as you feel comfortable with... as open or as closed as you want to be... family, education, work, hobbies, etc.
Troy Dawson: My name is Troy Dawson. I have a Bachelors degree in Physics and a Masters degree in Computer Science. I have worked at Fermilab since 1993. I was initially an accelerator operator, and then transferred over to computing in 1999.
I've been working with Linux since 1999.
I am married with two kids. I am very active in my church. I think my main hobbies are family, church, and computers.
There have been a few occasions where I have wanted to install CentOS on a remote machine that already had a working flavor of Linux on it. Luckily RHEL / CentOS has a way to do this.
- Download the PXE CentOS kernel and initrd image
- Configure the bootloader to boot the CentOS kernel by default
- Configure the bootloader with extra parameters for networking and remote VNC
- Reboot the machine
- Run the vncviewer in listen mode with port 5500 accessible
Recently a GNOME survey (aka the Neary report) came out that showed who contributes to GNOME and at what levels. Not so oddly enough the results of it turned out similarly to periodic Linux kernel surveys done by LWN and Greg KH. The results being that Red Hat is the top named contributor.
It just so happens that Canonical (the sponsor of Ubuntu) typically does not fair so well on such surveys and as a result they are often criticized for their perceived lack of upstream contributions.
Automating Configuration, Deployment and Maintenance for Red Hat and CentOS by Kay Williams from Rendition Software.
I sent this to the centos-virt mailing list today... and thought I'd share it here as well.
I'm a big OpenVZ fanboy. I've sent a few emails on this list that proves that... and I'm sure I've annoyed some people... but be that as it may... I would like to draw everyone on this list's attention to Proxmox VE. What is Proxmox VE?
OpenVZ and KVM are Linux based virtualization programs, both are part of the Proxmox VE distribution. The goal of this article is to provide some knowledge on moving physical machines to virtual containers (OpenVZ) or fully virtualized machines (KVM). This article is not specific to Proxmox VE and the principles outlined and scripts provided should work on "stock" KVM or OpenVZ machines with a few minor changes to path settings.
Please note that the OpenVZ kernel is a product of the OpenVZ Project and is NOT supported by CentOS. The OpenVZ Project follows the RHEL kernels closely and provides updates in a somewhat timely fashion after updated Red Hat (and CentOS) kernels are released. As a result the RHEL-based OpenVZ kernels are well suited for use on RHEL and CentOS hosts with support for (almost) all of the same hardware. Please note though that the OpenVZ kernel is less modular than the stock Red Hat / CentOS kernels with some hardware support being compiled in. It is recommended you read this HOWTO in its entirety before attempting any of the operations shown in it.
What is OpenVZ?
OpenVZ is operating system-level virtualization based on a modified Linux kernel that allows a physical server to run multiple isolated instances known as containers, virtual private servers (VPS), or virtual environments (VE). The preferred term these days is container. Containers are sometimes compared to chroot or jail type environments but containers are really much better in terms of isolation, security, functionality, and resource management.
OpenVZ consists of a custom Linux kernel (available from the OpenVZ Project) and some user-level tools. OpenVZ is very portable, does not rely on VT support in the CPU, and as a result it is available for a number of CPU families including x86, x86-64, IA-64, PowerPC and SPARC.
OS-level virtualization is quite different from machine / hardware virtualization products such as VMware Server, Parallels Workstation, VirtualBox, QEMU, KVM, and Xen in that with OpenVZ you can only do Linux on Linux virtualization.
OpenVZ modifies the Linux kernel to add advanced containerization features which allow for isolated groups of processes under a parent init along with about twenty dynamic resource management parameters for controlling container resource usage. The OpenVZ Project maintains three stable kernel branches:
- RHEL4 / CentOS4 2.6.9 based
- RHEL5 / CentOS 5 2.6.18 based
- Vanilla 2.6.18 based
There are a number of unstable branches based on newer versions of the Linux kernel that may eventually reach stable status.
I am in need of a little help or a point in the right direction with some SSH & RSYNC stuff I'm trying.
Using CentOS 5 I am trying to automate some rsync tasks through ssh. I have CentOS5 on the destination too. I have a DSA and RSA key generated and scp'd onto the destination server. Essentially I am trying to do a host authentication to get around the password. The destination server is a production system so I can't lax much on the security or this would be much easier.
I have been trying to use some instruction from the rsync site as well as linuxquestions but I'm not making any real headway. The usernames are different for the source and destination systems but that shouldn't really matter for RSA/DSA authentication, should it?
Any help or refernces you could give me would be hot!
On another note, eventually I'll get to one of the LUG meetings. At least this month I made it to MSO but forgot my directions to Sean Kelly's. 8^p
"only the strong of heart can win to the place of the Vision!"
IN GHOSTLY JAPAN
I use the SystemRescueCD a lot at work. My work study scoffed at me for actually running it from CD rather than a USB stick... because the USB stick is much faster. I bought a three pack of SanDisk Cruzer Micro 2GB USB thumb drives from CostCo for about $50. I followed the SystemRescueCD instructions and bingo it worked. Ok, it boots up a lot faster now.
I applied the Fedora method to the recently released CentOS 5.1 LiveCD and that worked too. I guess the same principle would apply to any LiveCD .iso you'd want to throw at it... including regular distro install media. They even have a program for Windows users.
I noticed a blog posting by Daniel Veillard on Fedora People about initial support for OpenVZ being added to libvirt. If you aren't familiar with libvirt, it is an underlying library/API that can be used by higher level tools to create, manage, and monitor virtual machines. libvirt is trying to be technology agnostic by supporting several virtualization technologies. They started off with Xen and QEMU but have since added KVM. libvirt is used by the GUI tool Virtual Machine Manager which first appeared in Fedora Core (now Fedora) but became part of Red Hat Enterprise Linux 5.
Looking at some of the postings in the libvirt mailing list archive for this month, it is mentioned that adding OpenVZ support is a bit different than previous technologies because the OpenVZ tools are already GPLed, "simple and straight forward", and than OpenVZ additions to libvirt "ends up looking very close to the original". I don't know how far away complete support for OpenVZ is in libvirt nor when it will show up in Virtual Machine Manager but I definitely look forward to it... although I doubt it would completely replace vzctl and the other OpenVZ tools for me.