Linux KVM Hypervisor Thoughts

[Lazybones]

Just some thoughts on KVM after playing around with it:

Pros:
- Unlike Zen it allows you access to software RAID since it is part of the kernel not loaded before it.
- Virt-Manager is very basic but works as a Linux only GUI
- If linux supports the hardware you can probably use it with the KVM Host
- If you can get the managment GUIs going it seems like a really good platform for home visualization if you don't have ESXi compatible hardware (hard or expensive with consumer HW) or don't want to license Win8 or Windows server with Hyper-V

Con:
- Nearly all the nice Web-UI projects are complicated or RedHat only focused (not a problem if RedHat is your preferred linux)
- Seems like all the enterprise like features are a mixed bag... You don't standardize on KVM for HA you have to implement a whole management platform server cluster 3rd party tools to do it.
- Not as easy as Hyper-V or ESXi

[Tom]

Yeah, KVM needs some work in order to be more useful as a platform. I like it because its there and included. Don't have to set up anything else.

[Lazybones]

Yeah, KVM needs some work in order to be more useful as a platform. I like it because its there and included. Don't have to set up anything else.

Setup wise you do need to add management tools like Virt-Manager, the command line isn't that intuitive and is rather verbose.

Not that I have KVM setup one area of improvement I plan is to stop sharing data over the network with the guest OS and instead share the volume via KVM for direct access.

[Tom]

Ah, yeah. I use libvirt/Virt-Manager because its too much a pain in the ass to do manually. and it works "well enough" to get the job done.

My vm's live on LVM volumes, so they do get their own block devices. I suppose if I was to run say freenas in KVM, i'd actually export the raw hdd devices, and let the guest manage them itself. especially if it was doing something like ZFS (but ZFS is a stupidly huge memory hog....).

[Lazybones]

I went with qcow2 to keep the images sparse.. All large data needs are served by the host over share, or in the future mapping .

[Tom]

Yeah, I just found it simple enough to use LVM since libvirt supported allocating them in the app directly. and I already had a lvm group setup, so why not use it?

[Lazybones]

What ever works best. LVMs probably have significant performance benefits over the compressed qcow2 files.

[Tom]

Yeah, that's probably the main reason I went that route. My old Xen setup had really slow disk access and it used disk images. I was not happy with it at all.

[Lazybones]

Ya my VMs don't do a lot of expanding so image files arnt bad and are distinctly easy to port, backup and restore.