Comments on: The Future of Xen http://etbe.coker.com.au/2008/05/02/the-future-of-xen/ Linux, politics, and other interesting things Wed, 08 Feb 2012 17:45:05 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: geb http://etbe.coker.com.au/2008/05/02/the-future-of-xen/comment-page-1/#comment-13470 geb Sat, 03 May 2008 12:33:04 +0000 http://etbe.coker.com.au/?p=578#comment-13470 thx to intel, the new bios even broke systems with 4GB, so yes it's an bios issue which is there since last year thx to intel, the new bios even broke systems with 4GB, so yes it’s an bios issue which is there since last year

]]> By: etbe http://etbe.coker.com.au/2008/05/02/the-future-of-xen/comment-page-1/#comment-13467 etbe Sat, 03 May 2008 11:03:56 +0000 http://etbe.coker.com.au/?p=578#comment-13467 tbl: Thanks for the suggestion, it's interesting to know how other Unix systems work with Xen. Generally I don't have enough time to learn about the other distributions of Linux, let alone other Unix systems. Stefano: My understanding of OpenVZ is that it's like VServer in it's design. This doesn't work for some of the things I want to do as I want to run different kernel versions as DomU's (or equivalent). Jeff: Thanks, I should have tried that before upgrading to Unstable. specialj: My laptop doesn't get much travel nowadays, mostly it's moved between desks and even when running Xen the batteries last the duration of the journey. But you are correct that it is a problem with Xen and a win for KVM. Anon: I liked it when they had different names, Pentium 3, Pentium 4, Pentium D, and different clock speeds and cache sizes within that range. They stuffed it up a little by releasing both 32bit and 64bit chips under the name "Celeron D" and then abandoned it entirely in recent times. geb: That sounds like a BIOS issue, so probably a new BIOS will fix it. Not that it matters for me, after all the pain of this upgrade I'm even less enthusiastic about further upgrades. 3G is enough for what I want to do though, so I should be able to keep using the same hardware for at least another 5 years for that server. tbl: Thanks for the suggestion, it’s interesting to know how other Unix systems work with Xen. Generally I don’t have enough time to learn about the other distributions of Linux, let alone other Unix systems.

Stefano: My understanding of OpenVZ is that it’s like VServer in it’s design. This doesn’t work for some of the things I want to do as I want to run different kernel versions as DomU’s (or equivalent).

Jeff: Thanks, I should have tried that before upgrading to Unstable.

specialj: My laptop doesn’t get much travel nowadays, mostly it’s moved between desks and even when running Xen the batteries last the duration of the journey. But you are correct that it is a problem with Xen and a win for KVM.

Anon: I liked it when they had different names, Pentium 3, Pentium 4, Pentium D, and different clock speeds and cache sizes within that range. They stuffed it up a little by releasing both 32bit and 64bit chips under the name “Celeron D” and then abandoned it entirely in recent times.

geb: That sounds like a BIOS issue, so probably a new BIOS will fix it. Not that it matters for me, after all the pain of this upgrade I’m even less enthusiastic about further upgrades. 3G is enough for what I want to do though, so I should be able to keep using the same hardware for at least another 5 years for that server.

]]> By: geb http://etbe.coker.com.au/2008/05/02/the-future-of-xen/comment-page-1/#comment-13454 geb Sat, 03 May 2008 07:15:23 +0000 http://etbe.coker.com.au/?p=578#comment-13454 even if the intel board is supposed to support 8GB ram, it breaks horribel. http://gebi.supersized.org/archives/2-Intel-965-board-with-8GB-Ram-and-Linux.html even if the intel board is supposed to support 8GB ram, it breaks horribel.
http://gebi.supersized.org/archives/2-Intel-965-board-with-8GB-Ram-and-Linux.html

]]> By: Anonymous http://etbe.coker.com.au/2008/05/02/the-future-of-xen/comment-page-1/#comment-13453 Anonymous Sat, 03 May 2008 06:32:41 +0000 http://etbe.coker.com.au/?p=578#comment-13453 Go figure. People complained when Intel used and promoted processor speeds, and now they complain when Intel switches to an arbitrary performance/feature metric. Go figure. People complained when Intel used and promoted processor speeds, and now they complain when Intel switches to an arbitrary performance/feature metric.

]]> By: specialj http://etbe.coker.com.au/2008/05/02/the-future-of-xen/comment-page-1/#comment-13441 specialj Fri, 02 May 2008 22:46:59 +0000 http://etbe.coker.com.au/?p=578#comment-13441 My current setup is to use Xen on servers and KVM on desktops (if the hardware support is present). For your Pentium-M laptop I'd think that VirtualBox might be the best solution since you have neither 64-bit support nor VT support, with the caveat that you may want to replace it with KVM should you ever upgrade. I can sympathize with your Xen problems. Right now all of my Ubuntu DomU's are unable to be upgraded from 7.10 to 8.04 due to a bug in the kernel that causes similar problems to what you mentioned. Perhaps it would shed some light on your issues: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/218126 However, it makes no sense to use Xen on a laptop due to Xen lacking power management facilities. If Xen ever gets CPU throttling support I would be quite happy, and perhaps if KVM can catch up in other areas it might be a reason to switch, even on the server (electricity is expensive). I haven't replicated tests recently but in the past I found KVM to be unsuitable for servers. For one thing it requires hardware virtualization support which not all of my servers have. Beyond that I found the scheduling to be sub-par. Xen is the only virtualization software I've used that fairly allocates resources. This can be tested by generating a high load in one domain and testing the responsiveness of the others. As with all software it's important to find the right tool for the right job and to keep your eyes on the other tools people are using. My current setup is to use Xen on servers and KVM on desktops (if the hardware support is present). For your Pentium-M laptop I’d think that VirtualBox might be the best solution since you have neither 64-bit support nor VT support, with the caveat that you may want to replace it with KVM should you ever upgrade.

I can sympathize with your Xen problems. Right now all of my Ubuntu DomU’s are unable to be upgraded from 7.10 to 8.04 due to a bug in the kernel that causes similar problems to what you mentioned. Perhaps it would shed some light on your issues:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/218126

However, it makes no sense to use Xen on a laptop due to Xen lacking power management facilities. If Xen ever gets CPU throttling support I would be quite happy, and perhaps if KVM can catch up in other areas it might be a reason to switch, even on the server (electricity is expensive). I haven’t replicated tests recently but in the past I found KVM to be unsuitable for servers. For one thing it requires hardware virtualization support which not all of my servers have. Beyond that I found the scheduling to be sub-par. Xen is the only virtualization software I’ve used that fairly allocates resources. This can be tested by generating a high load in one domain and testing the responsiveness of the others.

As with all software it’s important to find the right tool for the right job and to keep your eyes on the other tools people are using.

]]> By: Jeff Licquia http://etbe.coker.com.au/2008/05/02/the-future-of-xen/comment-page-1/#comment-13439 Jeff Licquia Fri, 02 May 2008 21:10:43 +0000 http://etbe.coker.com.au/?p=578#comment-13439 FWIW, etch-backports has Xen 3.2. I'm currently struggling with qemu-dm, which doesn't seem to work at all, but from the sounds of it that's less of a concern for you. FWIW, etch-backports has Xen 3.2. I’m currently struggling with qemu-dm, which doesn’t seem to work at all, but from the sounds of it that’s less of a concern for you.

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