[SOLVED] Hypervisor on Slackware

igadoter · 03-12-2021, 01:58 AM

Last time I had yet another difficult discussion here - but finally it appeared to be fruitful to me - so first conclusion do not avoid difficult discussions. Well problem was about EOL of 5.10 kernel. I posted I never upgrade system - always create something new. So I asked myself: what do you want to do with 5.10 release? If I am not satisfied with 5.10 - is there solution? And then bum: eureka. I always was interested in virtualization - but if you don't use it on every day routine - you don't learn much about it. So I said to myself: your new 5.10 installation will be totally virtual. Default target is system running in VM. However there is problem: I need to choose system for hypervisor. I plan to use next Slackware release but with 5.4 kernel as supervisor. Now the question is: does Slackware is ready to be hypervisor?

Edit: Word of explanation. There are Linux distributions which are ready to play such role - but most of them are systemd based - and as many years Slackware user I don't want to learn systemd. Waste of time. So essentially it would be easier for me to run FreeBSD. Or perhaps Debian on FreeBSD kernel - but I am not sure Debian on FreeBSD is systemd free. This is why I think about Slackware - to avoid systemd. And I also excluded all rolling-release distributions. So as you see I really don't have much choice.

Slax-Dude · 03-12-2021, 03:00 AM

I use qemu every day at work, managed by virt-manager, running on slackware64-14.2
Never had an issue with it. Works as advertised.
My "work PC" is a win10 VM running on slackware

deNiro · 03-12-2021, 03:14 AM

If you don't like 5.10 kernel, just run 5.4.xx kernel. I'm running 5.4.xx on slackware current. Works fine. virt-manager, qemu and libvirt are on slackbuilds. and for bridged networking you don't have to add anything. You can just create the bridged interface IFNAME[0]="br0" with a static ip and link that with BRNICS[0]="eth0" to your physical interface in rc.inet1.conf.

Since I don't run a whole lot of virtual servers, and I only have a desktop and laptop, I ended up with virtualbox. Since I prefer the ease of use with that one. And thanks to the one that maintains the virtualbox on slackbuilds, it was very easy to install that. Plus it only required 3 packages, nl. acpica, virtualbox-kernel and virtualbox. The performance of virtualbox has improved a lot since version 6.

For libvirt with some ease of use gui it required a lot more effort and packages. But it probably depends on what you want. If you want learn kvm and stuff, then go for kvm. If it's for a server it's better to go for kvm. but If it's just for running some virtual machine to test some stuff, I find it easier to use virtualbox.

rkelsen · 03-12-2021, 03:18 AM

Quote:

Originally Posted by igadoter

So I said to myself: your new 5.10 installation will be totally virtual. Default target is system running in VM.

OK. Good plan.

Quote:

Originally Posted by igadoter

Now the question is: does Slackware is ready to be hypervisor?

The answer to this question is: It depends upon how you want to do this.

If your goal is to use LXC (i.e. not really virtualised), then Slackware is ready with nothing extra required.

If, however, you want to use a VM, then you will have to install some extra software. There are several options, all of which will work with Slackware:

VirtualBox: https://www.virtualbox.org/

QEMU/KVM https://www.qemu.org/

BOCHS http://bochs.sourceforge.net/

My favourite is VB. It is easy to use and works quite well under Slackware. I use the installer from their website.

Gerard Lally · 03-12-2021, 04:39 AM

A recent Alpine Linux had 5.4 kernel. Xen and kvm hypervisors. No systemd. NetBSD is another option for an ultra lightweight hypervisor, with good Xen support and also the recently introduced nvmm.

igadoter · 03-12-2021, 05:52 AM

There are problems, say what about swap? To have swap on virtual hard drive? Sharing files between VM's? With VirtualBox there is shared folder - but this require user on host. And this always problem due to ownership. Constant size virtual hard drive?

deNiro · 03-12-2021, 05:58 AM

Quote:

Originally Posted by igadoter

There are problems, say what about swap? To have swap on virtual hard drive? Sharing files between VM's? With VirtualBox there is shared folder - but this require user on host. And this always problem due to ownership. Constant size virtual hard drive?

why are there problems with swap?? You would just configure a virtual system like on bare metal. with a swap partition on the virtual drive. And you don't absolutely need to use shared folders to share files. there is nfs, there is ssh, ftp. Plenty of options. And concerning the size of the drive, you can configure it so it will dynamically grow. or add extra virtual drives. It seems you are just looking for problems, instead of just make use of it.

rkelsen · 03-12-2021, 06:19 AM

Quote:

Originally Posted by igadoter

There are problems, say what about swap? To have swap on virtual hard drive?

Yes. Absolutely.

Quote:

Originally Posted by igadoter

Sharing files between VM's?

Between Linux VMs = NFS.

Linux to Windows = Samba.

It's not difficult. These solutions have been around for a very long time.

Quote:

Originally Posted by igadoter

Constant size virtual hard drive?

As per above, you're looking for problems which don't exist... The hair inside the egg.

igadoter · 03-12-2021, 06:21 AM

Swap is a partition - windows is using file for this. I mean difference is partition is continous part of hard drive - swap file not - and to put swap on dynamic virtual drive? So how it works? Does it possible to grow file size about 2 GB because of swap dump? I mean fast enough. Once virtual hard drive will became fragmented system may slow down. So I need to rethink things - because that VM will be my everyday drive. And I don't want it to stop to work after a year.

Tonus · 03-12-2021, 06:22 AM

I use qemu and share folders work very well.

Sending from phone, can't check if all is correct

To have share mounted change /etc/rc.local in guest

Code:

insmod /lib/modules/$(uname -r)/kernel/fs/9p/9p.ko && mount -t 9p -o trans=virtio,version=9p2000.L repos /mnt/hd

My qemu command on host

Code:

qemu-system-x86_64 -enable-kvm -smp cpus=2 -smp maxcpus=3 \
				-m 4096 -k fr -daemonize -vga virtio -boot menu=on \
				-usb -drive file=slackware64-current_snapshot.qcow \
				-cdrom slackware64-current-iso/slackware64-current-install-dvd.iso \
				-fsdev local,id=repos,path=/mnt/repo/Sandbox,security_model=none \
				-device virtio-9p-pci,fsdev=repos,mount_tag=repos"

igadoter · 03-12-2021, 06:23 AM

Quote:

Originally Posted by rkelsen

Between Linux VMs = NFS.
Linux to Windows = Samba.

Where am I supposed to set up these servers?

Edit: I think I need to be very precise on this - perhaps people here don't quite well understand what it is about. I am not asking how to run this or another VM's on Slackware. In contrary. It is how to run Slackware in VM but the first is to choose OS for hypervisor - so Slackware is good choice? I posted I don't want hypervisor with systemd - this why I am thinking about Slackware. Hypervisor is something different than OS with a couple of VM's on it. Say hypervisor does not even require common user account. Slackware as hypervisor means to install only what necessary. While Slackware full runs in VM. Slackware on Slackware.

rkelsen · 03-12-2021, 06:38 AM

Quote:

Originally Posted by igadoter

Swap is a partition

Right. So create a partition for it on the virtual disk.

Quote:

Originally Posted by igadoter

So I need to rethink things - because that VM will be my everyday drive. And I don't want it to stop to work after a year.

You're over thinking it. VMs have been around for a long time. These problems you're dreaming up have long been solved.

rkelsen · 03-12-2021, 06:40 AM

Quote:

Originally Posted by igadoter

Quote:

Originally Posted by rkelsen

Between Linux VMs = NFS.
Linux to Windows = Samba.

Where am I supposed to set up these servers?

On the VMs you want to share files between.

igadoter · 03-12-2021, 06:44 AM

Quote:

Originally Posted by rkelsen

Right. So create a partition for it on the virtual disk.

You're over thinking it. VMs have been around for a long time. These problems you're dreaming up have long been solved.

Perhaps, but you know it is my computer, my data and so on. Again seems we don't understand each other - it is not about VM's. Read the thread title. Or you try to tell the problems how to run Slackware as hypevisor were solved long ago. Or perhaps we have understand in the different way the word 'hypervisor'.

rkelsen · 03-12-2021, 06:49 AM

There are two types of hypervisor. A type 1 hypervisor is very thin and is not an operating system in it's own right. These are ESXi, Xen, Proxmox, etc. Slackware is not one of those, and cannot become one without significant work.

However, as a host OS running underneath a type 2 hypervisor, (Virtual box, Qemu, Bochs), Slackware is stable and capable.

Does that answer your question?

I'll add that if you're wanting to use Linux containers, Slackware is also excellent for that.