On 7/8/21 5:26 am, Arnt Karlsen wrote:
> On Fri, 6 Aug 2021 20:20:15 +0800, Brad wrote in message
> <a02bce2c-6bee-2fad-875e-336020fa959e@???>:
>
>> On 6/8/21 5:12 pm, Andrzej Peszynski wrote:
>>>
>>>
>>> On 06.08.2021 06:25, Brad Campbell via Dng wrote:
>>>>
>>>> Why do you even need/want libvirt? I have several machines which
>>>> run qemu guests just using simple bash scripts to bring them up
>>>> (and all the bash script is there for is to hold the command line
>>>> parameters). I like libvirt and virt-manager for configuring and
>>>> customising the guests, but at the end of the day all that is is a
>>>> fancy front end to qemu.
>>> <snip>
>>>> If you are stripping the guts out of libvirt, why use it in the
>>>> first place?
>>> Brad, thanks a million! Learning is fun especially for a "apt
>>> install" man as I am. I am looking now at how I can simplify all
>>> this (may be stripping parts of QEMU too?), to keep running, and
>>> handle my configurations and resources binding. In the end, all
>>> what I need is executing in isolated ring the ELF of dozen of (not
>>> trusted) proxies, servers and libraries + resources balancing +
>>> isolated filesystems + sockets.
>>>
>>> From the other side, I think that the Type 1 hypervisor for desktop
>>> is also interesting thing, It's very tempting to have windowed
>>> multimachine with realtime switch capability.
>
> ..I get the idea that Andrzej and I are looking for Brad's kinda bare
> metal hypervisor Devuan install?
> We might come up with minimal net-install size install image as an
> alternative to https://en.wikipedia.org/wiki/Qubes_OS , only without
> systemd and based on Devuan.

I'm not quite sure how my description of a self-compiled (ancient) libvirt install qualifies as "bare metal".

> ..in Debian and Devuan we often have package conflict that means hold
> back upgrades or ditch good software we'd like to keep, those conflicts
> disappears when we can contain each of those old or new things in e.g.
> a vm.
>
>> I mostly do that and have done for over 20 years now.
>> My desktop is essentially a moderately powered thin client (currently
>> a 2011 iMac27 with 2 27" thunderbolt displays running Beowulf). On
>> the server side :
>
> ..running on that same 2011 vintage iMac27?

Yes, 3 27" displays managed by xmonad. Enough screen realestate to go around.

>> - A Dual head windows 8 VM for Autodesk products & MS Office.
>> - A Dual head
>
> ..meaning 2 27" physical displays on top of each client's desk?

Meaning I have 2 27" heads on the VM that display on 2 of my 3 27" displays on the desktop.
Being able to use more than one display on a windows VM revolutionized my VM use.

>> windows 10 VM for newer Autodesk products that won't
>> run on Windows 8.
>> - A Debian wheezy / xfce VM for a specific older version of
>> Openoffice.
>
> ..I have some old hw running Debian Sarge thru Wheezy, can I simply
> yank out those old disks and run them off a vm each?
> Junk's still useful as guinea pig rigs. ;o)

Might need a little tweak here or there, but sure. I've run VMs off dedicated drives. Right now the CCTV server has 4 8TB drives passed straight through.

>> - A Windows 8 VM with a CCTV server.
>
> ..is that running better than e.g. motion or zoneminder, or just
> based on company policy?

Part of what I do is work with numerous CCTV systems. I've never found anything open source that was worth a second look.

>> - A Devuan Ascii / XFCE VM for Peer to peer.
>> - A Devuan Ascii headless VM for Cacti, HLI to the HVAC system and
>> some general development and plumbing
>> - Numerous VMs with specific build configurations for embedded
>> software.
>>
>> The other thing VMs are good for is tying up Scam call-center
>> workers. "My windows is full of viruses you say? And you can help me
>> with that? Brilliant, just let me sit down and start my computer
>> up" (spins up a fresh clean windows VM I prepared earlier)
>
> ..ooo, and with a nice juicy tarpit too? :o)

Yep, useful for honeypots also.

>> Win4lin, bochs and sheepshaver were brilliant, then qemu came and
>> conquered. I can't imagine ever running Windows on the bare metal
>> again.
>>
>> Between spice and rdp, there's not much you can't do.
>>
>> Brad
>
> ..I get the impression you have what we're looking for here.
> Your 'dpkg --get-selections' would get us started, you also
> have ideas on how to best set up our own configurations.
>

I really don't have a "minimal" install. To get what I have, a basic beowulf install with the addition of the packaged libvirt would be almost there.
I'm not fanatical about the minimalist approach. Storage is cheap and my time isn't. The server also runs :
- exim/dovecot
- openvpn server
- cups
- custom ghostscript filters
- apache
- bind
- dhcpd
- handbrake
- mariadb
- postgres
- samba

There's years of cruft here :

srv:~# dpkg --get-selections | wc -l
1612

Heck, a new machine with a clean install I spun up last week (minimal beouwlf with libvirt) :
root@XXXXXX:~# dpkg --get-selections | wc -l
1094

Not really minimal, but it took minutes to install and get running.

I use VMs a "lot", but really have no use for a "minimalist" hypervisor install.

I think you really need to do some experiments and figure out what perceived overhead/risk you are going to incur by using the packaged software on a minimalist beowulf install and figure out what you are really trying to achieve when you say "bare metal". I can't imagine any of it being more than a bit of extra disk space. I know it'll make zero difference to the guests.