Re: [gentoo-user] libvirt

[Michael Mol]

On Mon, Dec 3, 2012 at 10:19 AM, Michael Hampicke <gentoo-user@××××.biz> wrote:
>>> Do you need a virsh command, or is it enough to know libvirt supports?
>>> In the second case you might look at [1]
>>
>> Well, given that I'm on gentoo, USE flags start getting involved in
>> enabling and disabling functionality. Rather than actively examining
>> the compile-time factors, I was hoping for a way to simply ask
>> libvirtd via virsh. Going that route gives me an approach that works
>> weather I'm on Gentoo, Linux, Debian or whatever.
>>
>
> Good point. Virsh should at least tell you what storage pool support has
> been enabled while compiling. That would still leave you with another
> problem: Even if iSCSI or LVM support has been enabled, it doesn't mean
> you can actually use it on that host (maybe no kernel support, not
> configured, maybe no disk in node, ...)
>
> In virsh there's a find-storage-pool-sources command, sadly there's
> almost no documentation. On my testing machine it is at least able to
> discover the LVM.
>
> virsh # find-storage-pool-sources logical
> <sources>
>   <source>
>     <device path='/dev/sdb6'/>
>     <name>kvm1</name>
>     <format type='lvm2'/>
>   </source>
> </sources>

After digging through the docs a little more, I'm almost certainly
going with 'directory'. Later, it'll be NFS. I'm surprised it didn't
offer you either of those options...but I guess it was looking for
fully-configured things.

>
>>> You also might take a look at virt-manager (in portage) which is a gui
>>> for libvirt that manages libvirt on your local machine an remote
>>> machines (via ssh tunnel for example).
>>
>> I've played with virt-manager before. I could use it again, but at
>> least part of this exercise is to learn libvirt and kvm using a
>> spartan toolchain. So I'm trying to do everything I can via CLI. (I'm
>> handy enough with Python that I could use the python API bindings, but
>> I presumed virsh would be easier, if not simpler.)
>
> Yeah, I was a hardcore kvm user once too :) No libvirt installed, just
> pure kvm, did everything on cli, creating images, setting up the virtual
> network, starting kvm vms by hand with a big-ass argument list, ... I
> guess I just got lazy :)

Actually more familiar with Xen. I'm going with kvm on this one
bevause virtualbox on a debian system doesn't give me the flexibility
for network topology that I'm looking for...so I want to go with Linux
as a hypervisor and do the topology magic there.

Anyway, I'm of the opinion that once you understand what you're doing,
being lazy is the best thing you can be. But you have to understand
what you're doing in order to know when to be lazy. ^^

>
>>> I am really happy with virt-manager here, it work very well on you don't
>>> need to remember all the virsh commands (which becomes pretty handy when
>>> managing storage, virtual networks and creating vms)
>>
>> Yeah, I'm hoping to learn all those commands. I want to
>> proof-of-concept an approach for a high-availability NFS server using
>> VMs.[2] :)
>
> Sounds interesting, I'll bookmark that.

Yeah, it's going to be fun. :)



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:wq