Learn about Linux
Download Linux
Get Linux helpSpecial Offers
Feature
Special report: Virtualization on Linux
Share
Print
CommentsWe're starting the series with Marc Abramowitz's look at Installing Linux-VServer, which, among other things, offers a concise explanation of paravirtualization versus full virtualization.
Over the next few days, we'll also look at VMware's Workstation and VMware Player, virtualization in the Linux kernel, User-Mode Linux, OpenVZ, and more. Of course, we've also looked at virtualization in the past -- in 2006 we covered VMware Server, Virtuozzo, Linux-VServer, VMware Player, and other virtualization solutions. We'll also continue to cover virtualization throughout 2007 as new products are released.
If you have a comment about this special report, or a suggestion for future coverage, drop us a line or leave us a comment. We'd like to hear what you have to say about the series and what you'd like to see covered in the future. Also feel free to talk about your own experiences with virtualization, how you're using it, what you're using, and recommendations for other readers.
Comments
on Special report: Virtualization on LinuxNote: Comments are owned by the poster. We are not responsible for their content.
I tried it just yesterday
and this even more:
couldn't change or edit a VM without going to the config file
I use VMware and it's graphical manager a lot, but if I can't use the config files with VI, I consider this program dangerous.
I'm interested. What are you using XEN for? Can you describe your Xen environment?
Almost anything requiring a Linux server: DNS, Squid, Mail relays, DBMS, Webserver.
It would not virtualize my memory
Is this a bug or a feature? For my way of thinking, memory allocation is the maximum memory I will need. I use the balloon function if I need on the fly changed. I would rather not have all my VM overusing the physical memory.
Crashed servers(Domain-0) are nice too
So is a defective MB or RAID controller. DOM-0 is for domain management only. Use it for any other need at own risk.
I don't use Novel, Groupwise or Exchange. Mind you, Caldera will not boot on VMware. Does this mean VMware is not ready for prime time?
I think you may have things confused. Those are transport protocols for connecting systems that are usually physical. For example, iSCSI is a transport protocol for carrying SCSI commands over an IP network to a remote disk system. But, the server(hardware at least) and the disk system are real/physical systems.
Virtualiztion is the substitution of logical entities for physical hardware that the guest operating system interprets as physical hardware allowing multiple operating system instances to share the same physical hardware.
What OS/distro are you hosting XEN on (Domain-0)?
Are you saying that you use XEN only for Linux guests and VMWare for everything else?
No, I use Windows on VMware and everything else on XEN. This might change where VT enabled servers are more common (read cheap)
What guests are you hosting on VMWare?
Windows 2003
What OS/distro are you hosting XEN on (Domain-0)?
Debian
Much more cool with an crash-proof computer system that can never crash unless there is an hardware failure. A system where a faulty designed software can never bring the whole system to its knees.
Or system with really good computer security that cant be exploited.
Or system that boots almost instantly or that I can just shutdown by pressing power button, without have to shut down the operating system.
Virtualization has been here for a while. It is also far from being new in the data centers.
It might be big in 2007, but more in the CEO targeted rags.
What I need is a special report on how to keep friends with hardware vendors. I am loosing them rapidly. Older PC's are being turned to Linux based thin clients of firewalls, and new servers hardware sales are lost as those systems disappear into the boules of XEN and VMware systems.
Xen?
Posted by: Anonymous Coward on January 09, 2007 10:36 PMAfter listening to the hype for the past two years, I tried it just yesterday and was underwhelmed, to say the least. I came away feeling that not only was it not ready for prime time but, that it was completely unusable in an enterprise environment.
What I didn't like:
It would not virtualize my memory, requiring that whatever amount of memory was allocated to a virtual machine(VM) decrease the available physical memory pool by that amount which severely limited the number of operating systems that I could run on it. So, if I have a 4GB of RAM machine 1GB goes to the host OS for Domain-0, I create 3 VMs and specify 1GB of RAM each and I'm done. The management interface won't even let me create another VM regardless of how many VMs are actually running or how much memory is actually in use!
The management interface sucked!!!! Using SuSE 10.2 I could create and delete VMs but, I couldn't change or edit a VM without going to the config file. I tried forcing the memory issue by altering the config files but, that ended with a crashed server(Domain-0).
Crashed servers(Domain-0) are nice too. Instead of losing a single machine I lose four at once! w00t!
It's using QEMU! I thought that XEN was a separate product. I can't figure out what Xen offers beyond QEMU.
They've been talking about the ability to migrate live virtual machines to different physical devices since at least 2005. But, this is unsupported today and for all intents and purposes can't be done.
Windows XP installs fine and seems to run OK but the boot CD of other OSes like Netware 6.5/OES, won't even boot! Furthermore, according to Novell, none of these OSes are officially supported to run as guests on XEN "just yet". Even in VT mode, which is how I tested since paravirtualization mode prevents the use of unmodified or binary only operating systems!
Windows Server 2000 and 2003 seem to work. I did not experience any problems with these OSes in limited testing but, what would I run on them? Can't run Exchange, SQL will suck, if it even runs. I guess I could have a bunch of Windows servers running IIS. Oh joy.
GroupWise? On Linux and maybe on Windows but not on Netware because it won't even install! I suspect that GroupWise performance would suck under XEN, but I could be wrong.
Exchange? Seems to work but, performance is utter shite and Microsoft doesn't support it at all!
Citrix? Virtualize a virtual environment? Ok, I'll try it. It seems to work but, it's not really stable and I can imagine that the next (as yet unknown) app that management wants installed on Citrix will be utterly unsupported incapable of running in a virtualized environment.
So, what do you use XEN for and how reliable is it? How do you backup your XEN system and your guests?
#