VirtualProx experiments 2021

I’ve written a ton of posts about running a Proxmox cluster in VirtualBox.

Part of why I write these things is to help me record work that I did in the past, kind of like a journal. Part of it is the hope that someone will read it and benefit from it. Mostly, building home lab shit and writing about it is how I cope with… *gestures vaguely*

The new Proxmox 7.X version is out, and the Proxmox Backup server has also been released. So I set up another Proxmox cluster in Virtual Box. Here are some observations and things that I learned from the exercise.

1. I learned enough about host only networks in Virtualbox to eliminate the need for a management workstation.
   I am a big fan of setting up a workstation with a GUI to test network configurations during the network construction phase. In the old days of hardware that meant using an old garbage PC, even though it was a waste of electricity. Now that we have virtualization, I still put a low powered VM on different subnets for troubleshooting. In those same old days when I was growing my Unix skills, I almost always used a Windows PC with multiple network cards because Windows has historically been completely stupid about VLANs and the like.

   Also, using a workstation with an OS that you are very comfortable with lets you focus on what you are learning. Trying to figure out a new OS while also figuring out networking, or virtualization, or scripting/programming is overwhelming. So, in previous labs, I recommended spinning up a basic VM that sat on the host only network for doing firewall/network administration tasks. Well, no more!

   It turns out that the IP address that you assign in the VirtualBox host network manager app is just the static IP address that your physical host has on that network interface. It’s not any sort of network configuration. I know that should have been obvious, but like the management workstation mentioned above, I am figuring this out as I go.

   

   So, when you are setting up your host only network interfaces, just pick any IP in the range that you want to use. I love the number 23, so that is the last octet that I pick for my physical host. If you set that IP to something other than .1 or .254 or any IP in your DHCP range, you can use the browser on your host computer to configure the ProxMox cluster. You will still need static IPs and multiple network interfaces for management, clustering, and the like.

2. Doing hardcore system administration tasks via the web UI has gotten a lot better
   My Unix/Linux skills are decent. Not as great as professional sysadmins, but better than most professional IT types. The same goes for my knowledge of networking and virtualization. I can hold a conversation with the folks that specialize in it. So, when I am trying to figure out ProxMox shit, I prefer the web UI so I am not getting out into the weeds chasing down Linux sytax issues or finding obscure things in config files, which I like to call Config File Fuckery(tm).

   You can configure the IPs for your interfaces with the UI, which didn’t work well in the past. You can also define your VLANs in the web UI, and change their names. I like for the VLAN ID/tag to correspond to the third octet of the assigned IP, so VLAN200 would have an IP of 192.168.200.0/24. Yes you can do vlan0 -> 192.168.0.0/24, but that’s no fun 🙂

   

   I have not yet figured out how to create a ZFS pool on a host using the web UI. You can create the pool as storage in the web UI, configuring your disks for use in the pool still requires the command line, as far as I can tell.

   Creating the cluster in the web UI is super simple now, but specifying a network for VM migration to another cluster node still requires editing the datacenter.cfg file as outlined in Part 3: Building the Cluster.

3. Proxmox backup server is just for backups
   
   Having a dedicated server for hosting backups is a great idea. Normally, I set up an NFS server as shared storage between the nodes, where I put container templates, ISO files, and snapshots of machines.

   Proxmox Backup Server integrates into your Proxmox datacenter as storage, and you can use it as a destination for backups. That part is pretty slick, but you can ONLY set it up as a target for backups.

   

   The other shared storage stuff, doesn’t look like it’s an option. At least not in the web UI.

   I am sure there is a reason for having one server for backups and another for shared storage, which probably has to do with tape drives. For my use case, I would like to download ISOs and container templates to one place and have it be available to all the cluster nodes, which requires an NFS server somewhere. I also want to use shared storage for backups, which could be a Proxmox Backup server OR the same NFS server that I would need for shared storage.

4. Running a backup server and a NAS seems like a waste
   I have seen forum posts about mounting an NFS share and using it as the datastore. I was more interested in doing the opposite, which is exporting an NFS share to the cluster nodes. It’s Debian Linux under the hood, and I can absolutely just create a directory on the root filesystem and export it. That’s not the point.

   

   I have also seen forum posts where users run the backup server as a VM. This is probably the use case for the NFS data store: keeping the files on a NAS and the backup software on a VM. I am contemplating doing the opposite, which is running the backup server on bare metal, and running the file server as a VM. I already have a hardware NAS that I am currently using as the shared storage for my hardware Proxmox cluster.

   In hardware news, I have acquired 3 rackmount servers for my hardware cluster. I don’t have a rack or anything to put them in, so stay tuned for some DIY rack making!

Adventures in Proxmox Part 3: Chris don’t know shit about networking

When I first started messing with Proxmox, I crashed my home network. If you aren’t interested in the story of my journey of network sexual awakening, click here.

I have since spent the last several months learning about Proxmox networking using virtual box. I have also been working on a parallel project: upgrading my home network to be segregated using VLANs. Like my budget for server hardware, my budget for network gear is practically nonexistent, so I have been doing a lot of reusing things that should have been replaced years ago.

After a bit of consternation, I settled on a prosumer router and a smart switch, rather than a PC-based router and a managed switch. Mostly because I needed this to work for the family as well as for the lab, and I didn’t want to spend weeks relearning Cisco. Time to tear down the old home network!!

A New Router

My plan is to have 4 “real” networks for my “physical” equipment:

1. The family’s wireless network – for phones, tablets, game consoles, and tv sticks.
2. My wired network for my personal workstations and servers.
3. A VOIP network for POE phones, ATAs, and my PBX.
4. A server and network lab for me to wreck things.

When I say “real” I really mean “operated by humans” or perhaps “not a Proxmox host”. When I say “physical” I also mean “operated by humans” or perhaps “not a Proxmox host”. At least half of these “real” ports are VLANs, and at least half of these “physical” devices are VMs. In this scenario, “real” and “physical” networks and devices are the ones that I and the family use, compared to the networks that are dedicated to the Proxmox cluster.

The critical distinction is that all of these network segments connect to a different port on the router, and have firewall rules to keep them from connecting to each other. In this scenario, a dumb switch plugged into each port of the router will provide a physically separated network at layer 2 (Ethernet) and a logically separated network at layer 3 (IP). It is here that I have used my first batch of dumb old mini switches:

1. eth1 – Family Wireless, 192.168.10.0/24
2. eth2 – Personal Wired, 192.168.11.0/24
3. eth3 – VOIP, 192.168.12.0/24
4. eth4 – Lab, 192.168.13.0/24

The family wireless network consists of 2 wireless access points, both with 4 dumb gigabit Ethernet ports:

1. WAP port 1 -> eth1 on the router, uplink to the Internet
2. WAP port 2 -> eth0 on the NAS appliance
3. WAP port 3 -> port 1 on the smart switch
4. WAP port 4 -> port 1 on the other WAP

So, I had my router set up, and plugging a laptop in to each dumb switch let me pull an IP from the DHCP server for the respective network segment. I was also able to browse the Internet. Awesome. I have managed to convert a big, clunky, error-prone network into four smaller error-prone networks. This is progress?

As far as the family is concerned, eth1 on the router is the network. Wireless access to both the Internet and to the data and media stored on the NAS. If I never plug in the smart switch then only I would notice. I have the WAP’s dumb switch plugged in to the smart switch because I have a media server VM on the Proxmox cluster that I want to put onto the wireless network to stream video to tablets, mobile phones and smart TVs. Because the cluster nodes only have 4 network ports, I need to put multiple network connections on to 1 of those network ports. This is where VLANs come into play. This is also where upgrading my knowledge of routing, switching, and firewalls comes in to play with Proxmox: putting the cluster onto all 4 of my network segments using just one network port from each node.

VLANs: everything you hate about dozens of dumb switches, plus virtualization

With the new router working, it’s time to configure the networks’ core: the smart switch.

VLANs are a great way to divide up a big physical switch into smaller virtual networks. A 24 port switch could be broken down into 4 networks, with a a varying number of ports in each network. You can also put a single switch port onto more than one VLAN. The network traffic gets put into the appropriate virtual network by using tags. You can even put a given port into “all” of the VLANs, this is sometimes referred to as a “trunk.” Trunks are used to connect multiple switches together, passing all tags between them.

Dumb switches can’t tag traffic. So, if you want to mix a smart switch that does VLANs with a dumb switch that doesn’t, you need to make sure that your untagged traffic is going out of the right ports. In the hypothetical 24 port managed switch in the example above, if you put port 2 into VLAN 2, and then plug a dumb switch into port 2, then port 2 needs to know what to do with untagged traffic. Traffic coming out of the dumb switch won’t have tags, and traffic going into to the smart switch will lose its tags. This is the essence of “VID” and “PID/PVID”. A VID is a VLAN ID, PVID is a Port VLAN ID. All the ports on the smart switch need to treat all traffic as tagged, even when it’s not. Untagged traffic needs to be treated differently than tagged traffic, basically meaning that “untagged” is just a special category of “tagged”. The PVID is a kind of “untagged == special tag” way for ports to deal with untagged traffic. This is the exact moment that I developed a migraine.

I have done a decent job keeping the family wireless network packets away from everything, and everything away from the family by putting each network segment on its own dumb switch. Now it is time to blur those boundaries a bit by plugging each of those dumb switches into the smart switch. My network is broken into 4 subnets, so my VLANs will break down something like this:

• VLAN 1 – Family Wireless
• VLAN 2 – Personal Wired
• VLAN 3 – VOIP
• VLAN 4 – Lab

I probably don’t need a separate /24 (class C) network for each VLAN, but I am not very clever and I have zero confidence in my ability to design networks or IP schemes. I know how routing works when you are using /24’s so for my implementation VLAN == /24. Also, as I learned in the Virtual Box lab, network designs get real confusing real fast, so having the VLAN tag roughly correspond to /24 subnet helps me to not go completely insane.

The smart switch is configured by a web interface. This interface has a default IP of 192.168.0.1, so I set a static IP on the Ethernet port of my laptop and logged in. This part of the configuration is important, and it will come into play again later. Once I have all the VLANs set up, I still need to be able to access the switch on this IP address.

I configured the first 4 ports on the switch as access ports or up-links to the dumb switches. Because the dumb switches don’t tag traffic, I needed the uplink ports to treat all “untagged” traffic as tagged to a single VLAN, using the PVID:

• switch port 1 – VLAN 1, PVID 1
• switch port 2 – VLAN 2, PVID 2
• switch port 3 – VLAN 3, PVID 3
• switch port 4 – VLAN 4, PVID 4

So now, if I change port 5 to VLAN 1 and PVID 1, I can plug in my Windows laptop and pull an IP from the wireless network. Then I can change port 5 to VLAN 2 and PVID 2, and now I can pull an IP from the wired network. Now I need to figure out how to get my Prox cluster nodes to sit on all 4 networks at the same time using a single switch port for each node.

Enter the Management Workstation

Up to this point, I was able to set up my dumb switches and my VLANs with a Windows laptop. I just disabled the WiFi and plugged the Ethernet adapter into the various switches and ports. This was fine for scenarios where one switch port corresponded to just one network segment. But it turns out that Windows can’t do VLANs without proper hardware and software support for the NIC. If you have a VLAN-aware NIC and the Intel or HP enterprise app to configure it, I guess it works fine, but there is no Windows 10 app for the Intel NIC in my crashtop.

In my Virtual Box Proxmox lab, I learned that life is just easier when you have a Linux box dedicated to managing the cluster and testing your network setup, so I decided that before I set up the cluster, I should set up a “Management Workstation.” For the BoxProx lab, I used a Virtual Box VM running a GUI to administer the cluster because I needed a browser on the host only network. Technically, I could have run the management workstation without a GUI and just used SSH tunneling to access the web management interfaces for the Proxmox VMs, but I didn’t want to spend any time doing stupid SSH tricks. I also don’t have the actual hardware cluster running yet, so I need to do this with actual hardware. The hope is that once I get the VLANS and network bridges configured, the workstation will be superfluous. Therefore, the workstation doesn’t have to be powerful at all. Literally any old laptop or desktop that is laying around will do nicely.

My operating system of choice is Turnkey Linux Core. Set up an old desktop on port 5 of the smart switch. For the initial install, I left port 5 configured for VLAN 1 and PVID 1. I was able to pull an IP address from the wireless network, install and update the OS, and configure SSH.

Remote access is important because I can’t sit in my basement all day; Internet access is important because I need to install some network tools.

First step is to get the VLAN tools installed:

apt-get install vlan

Then enable VLAN support in the kernel:

echo 8021q | tee -a /etc/modules

Then add your tagged network interfaces:

nano /etc/network/interfaces

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
    address 192.168.0.10
    netmask 255.255.255.0

auto eth0.1
iface eth0.1 inet static
    vlan-raw-device eth0
    address 192.168.1.10
    netmask 255.255.255.0
    gateway 192.168.1.1
    dns-nameservers 8.8.8.8 8.8.4.4

Then reboot the machine. I know there is a bunch of crap that you can do to avoid that, but this is the only way I can be sure that it works. I also know that if you name the interface eth0.N you probably don't have to mark the 'vlan-raw-device' but the Debian VLAN tutorial did it so I did it too.

What this does is change the IP of untagged interface eth0 to 192.168.0.10 (remember the IP of the switch from before?) and add eth0.1 (VLAN 1) with an IP of 192.168.1.10 and configured a default gateway and DNS for that interface.

Now, the machine should still be connected to the Internet, and you can modify port 5 on the smart switch to be in VLAN 1 and PVID 1.

If you can ping the IP for the smart switch (192.168.0.1), the IP of something on your wireless network (like an access point) as well as Google's DNS (8.8.8.8) then you are in good shape.

At this point, I left the basement and went upstairs. I connected my laptop to the family wireless network (192.168.1.0/24) to SSH into the workstation. Since I will be making modifications to the smart switch configuration, as well as the management workstation, I decided to configure PuTTy to drop a local port and forward it to 192.168.0.1:80 so that I can access the web interface of the smart switch from my laptop, and the unencrypted HTTP traffic will be secured by the SSH tunnel.

Now I just need to move the Internet access to the 'Lab" VLAN and add the remaining VLANS to /etc/network/interfaces:

nano /etc/network/interfaces

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
    address 192.168.0.10
    netmask 255.255.255.0

auto eth0.1
iface eth0.1 inet static
    vlan-raw-device eth0
    address 192.168.1.10
    netmask 255.255.255.0

auto eth0.2
iface eth0.2 inet static
    vlan-raw-device eth0
    address 192.168.2.5
    netmask 255.255.255.0

auto eth0.3
iface eth0.3 inet static
    vlan-raw-device eth0
    address 192.168.3.5
    netmask 255.255.255.0

auto eth0.4
iface eth0.4 inet static
    vlan-raw-device eth0
    address 192.168.4.5
    netmask 255.255.255.0
    gateway 192.168.4.1
    dns-nameservers 8.8.8.8 8.8.4.4

The last step is to make sure that smart switch port 5 is part of VLANs 1, 2, 3, and 4, with PVID 1. If all goes well, the workstation can ping the smart switch IP, Google DNS, and servers on all 4 VLANs.

The next step is to use this same network setup for the management NIC on the Proxmox cluster. Using the 4 VLAN interfaces for the network bridges (VMBR1-VMBR4).

Building a Proxmox Test Cluster in VirtualBox Part 5: Shit Happened; Lessons Were Learned

Jesus, it’s been almost a year since I posted part 1 of this series.

Hacking stuff is one of the ways that I cope with depression. Like going to the gym and getting stronger, learning new skills is a productive activity that improves my mind and my career. Also like going to the gym, hacking stuff requires a certain level of energy and focus. When I am having a depressive episode, I just can’t make myself do much more than watch TV. I have emerged from my Fallout 4 binge and I am eager to get this hardware cluster off the ground.

Learning Lessons

In my pursuit of a working Virtual Box + Proxmox cluster (Boxmox? ProxBox? BoxProx!) I discovered a few fatal flaws:

• My testbed is a single laptop, and I used static IP’s that sat on my internal wireless network.
• That meant that I could hack and demo the cluster at home, but not out in the world, like at Cinci2600.
• Ergo, the “Management interface sitting on the internal network” question that I excluded from the exercise should not have been excluded.
• Thus, the laptop-based lab for this project was missing a few things:
  1. 3 “Host Only” networks for the management interface, cluster network, and migration network.
  2. A router VBVM to route traffic bound for the Internet via a NAT interface.
  3. A management workstation VBVM with a GUI, for managing the router and the BoxProx CLI and UI.

The reason that I have been doing all of this in Virtual Box, is because it’s easy to recover from these sorts of mistakes. You can think of this exercise as the “Lab Before The Lab”, or the development phase, before going to an actual hardware lab. I actually gave up on keeping my lab environment separate from my home network because I was always limited by one thing or another. At this point, it’s as much lab as it is production, pretty much everywhere.

Shit Happening
Another component of this exercise that I have not documented is the redesign of my home/lab network to accommodate the new cluster. The old “cluster” is down to two old Proxmox servers that aren’t clustered together. It works for getting shit done for the family (PBX, Plex, Bittorrent, OpenVPN, etc.) but it’s not optimal, nor is the network sufficiently segregated to my satisfaction. So, as I have been doing this, I have also been upgrading the home network and learning more about things like VLANs.

So, the material of the first 4 parts of the series is valid, I just wanted to include the router and workstation bits, which you will probably only need if you want your lab to be portable, and work on wireless networks other than your home.

Modification to the network design

In the first installment, I recommended using a bridged adapter for the management interface. This worked great at home, but once I went anywhere else, the wheels fell off the whole process. I tried things like adding a static IP to my wireless adapter in Windows, and I came to the conclusion that Windows just doesn’t do virtual networking like it’s supposed to.

So, when you build your PVE hosts, use 3 host only networks, and use a router VM to connect the cluster to the Internet. Also be sure to disable the DHCP service on all of your host-only networks, like so:

The router

I know I have made simple routers from Debian VMs but for this experiment I spent a fair amount of time in the weeds. So do yourself a favor and just use PFSense. Yes it’s waaaay overkill for what you want to use it for, but it will route packets between two networks with minimal configuration, and that’s really what you want.

1. Put the first interface of the PFSense VM on a NAT network.
2. Make sure to disable the DHCP server on your host-only network interfaces.
3. Put the second interface for the PFSense VM on the FIRST host-only network interface.



4. Once you have the VBVM booted up, configure the WAN interface on the NIC that was configured by DHCP, and the LAN interface on the other NIC.
5. Using the console on the router VBVM, configure the LAN for DHCP. Use a small address pool because there will probably be only one DHCP client ever. Using DHCP is an easy way to make sure that you are looking at the right NIC/virtual network.



6. I can tell you from experience that if you find yourself twiddling with PFSense settings, you are doing it wrong. Just factory reset the config and move on. This is a BoxProx lab, not a PFSense lab.

The Workstation

Ok, so now you have a small network on host-only adapter 1, and router that connects it to the NAT network on your computer. All these NATs make the cluster network portable, but all but useless for anything else. That’s fine. All you want at this point is for your Linux workstation VBVM to access the Internet despite the fact that its only network interface is sitting on a host-only network.

For the management workstation, you don’t need more than a browser and an SSH client, so literally any distro will work for you. I am a Debian guy, so when I want a no-frills GUI workstation with zero time spent configuring, I use one of the Ubuntu breeds meant for low end computers, like Lubuntu or Ubuntu Mate.

Regardless of the distro, you will be doing some repetitive typing in SSH. On Windows, I recommended MobaXTerm so you can type into multiple terminals at the same time and feel like a super hacker. In the Linux world, the app that you want to use is called “Terminator”. Like everything else on this blog, there is way more to Terminator that I won’t bother with. Just know that you can split your term into two equal parts horizontally and vertically by right clicking, and you can turn on and turn off broadcasting to all your keystrokes by pressing ALT+A and ALT+O respectively. Sorry Terminator/TMux/TWM fans, but I got shit to do.

This phase of the lab is a success if you can boot your Linux VBVM and use a browser to access Google as well as the web UIs for PFSense. You are now free to begin the lab again from Part 1.

Building a Proxmox Test Cluster in VirtualBox Part 4: Containers, Storage, and Replication

In the last installment in this series, I showed you how to build a cluster with separate interfaces dedicated to the cluster heartbeat traffic and to virtual machine migration. In order to see these in action, you need for your PVE hosts to run some VMs of their own. Once there are a three VMs running, we can play with the really great features of a Proxmox Cluster, like storage replication and high availability.

During the initial setup of the Proxmox hosts on VirtualBox, you probably saw an error message about KVM virtualization. I dismissed it as not a big deal. The truth is that this whole “virtualization inside of virtualization” exercise won’t produce any useful PVEVMs. I haven’t done much troubleshooting, but I am fairly certain that while the PVEVMs boot up and you can log into their consoles, they don’t really talk to each other or your physical internal network. That’s not as cool as I had hoped, but the point of this exercise was to figure out the network design for a Proxmox Cluster, not to play with cool double-layer virtual machines. I am sure that you can so some cool router Kung Fu to get them going for real, but for this exercise, PVEVMs booting up is enough. We’re just going to move them around the cluster so see how it all works.

Also, because each PVE cluster node is woefully under-powered, RAM is really at a premium:

So even if they did work as advertised, the PVEVM’s probably wouldn’t work well. Linux Containers are awesomely efficient, especially with RAM, but they can’t squeeze blood from a stone.

Downloading Templates and Building Containers

To build your PVEVMs you need to download a container template. It can be any of them. I prefer the LXC Debian 9 template or the Turnkey Linux Core template. How you want to go about building the test PVEVMs is your business, but the goal is 3 PVEVMs up and running. At different points in this exercise there will be one PVEVM running on each PVE cluster node, and all 3 PVEVMs running on one node. It’s up to you if you want to build them out:

• Download the template to one node, build the container, and then migrate it to another node, OR
• Download the template to each node and build each PVEVM from there, OR
• Download the template, build the container, and then clone it.
• The process is low as hell no matter how you slice it.

Once you have decided your approach, build 3 new containers. It takes a long time, but it demonstrates your need for a central data store for non-VM files. This is where a NAS would be handy. You could set up the NAS to store ISOs, container templates, and backups so that they would be accessible to all the nodes.

It’s important to note that you should build privileged containers. You do this by UN-checking the UN-privileged box. It’s stupid; I know.

At this point, you can migrate a container from one node to the other, but it takes a long time because you have to wait for the container to completely shut down, and then for the container files to completely copy from one cluster node to the next. On real hardware, this process will probably go a bit faster, but this is a good illustration of why we need storage replication.

Storage Replication

Before we can enable replication, we need to set up the ZFS storage properly. In the Building the Cluster Nodes post, we set up a ZFS array called ZStore, and now it’s time to set it up for the whole cluster.

In the Storage View for the cluster you have the option of adding storage. Here you will add a ZFS type and include the zstore/vmdata. Make sure to add all 3 nodes. I called mine “ZVMZ.” At this point it should be apparent that a RAID1 mirror, that is going to be replicated to 2 other mirrors is probably overkill in terms of redundancy, so you should probably do something different on your real hardware. If you have small but fast disks, you might RAID0 them to get nice write speeds, then replicate them for redundancy. Or do whatever.

Once the ZFS storage is set up for all of your nodes, you can move the storage for your PVEVMs to the ZVMZ storage. This will take a long time as well because everything has to copy over. This should be the last time you have to sit through a full copy of anything. Now we can set up replication.

Replication is done on a per VM and per host basis. So you will want to make sure that each VM has a job created to replicate to the other nodes. You only need two jobs for each VM. If you migrate a VM to another host, the replication job will update. The first time the job runs it will take a while. There isn’t a progress bar or anything, so you will have to check the ZVMZ storage on each node to make sure that there are copies of all of your VMs.

With replication set up, even if a cluster node fails, you will only lose 15 minutes (assuming you went with the default schedule) worth of data on the server and you can start up your server on another node with the snapshot. Migrate some VMs and see for yourself, and stay tuned for the next installment: High Availability.

Building a Proxmox Test Cluster in VirtualBox Part 3: Building The Cluster

In the last installment of this series, I discussed setting up the Proxmox VE hosts. Until now, you could do most of this configuring in triplicate with MobaXTerm. Now you can still use it to multicast, just be sure to disable it when you have to customize the configs for each host. This part of the process is a lethal combination of being really repetitive while also requiring a lot of attention to detail. This is also the point where it gets a bit like virtualization-inception: VirtualBox VMs which are PVE hosts to PVEVMs.

Network Adapter Configuration
I did my best to simplify the network design:

• There are 3 PVE hosts with corresponding management IP’s:
  1. prox1 – 192.168.1.101
  2. prox2 – 192.168.1.102
  3. prox3 – 192.168.1.103
• Each PVE host has 3 network adapters:
  1. Adapter 1: A Bridged Adapter that connects to the [physical] internal network.
  2. Adapter 2: Host only Adapter #2 that will serve as the [virtual] isolated cluster network.
  3. Adapter 3: Host only Adapter #3 that will serve as the [virtual] dedicated migration network.



• Each network adapter plugs into a different [virtual] network segment with a different ip range:
  1. Adapter 1 (enp0s3) – 192.168.1.0/24
  2. Adapter 2 (enp0s8) – 192.168.2.0/24
  3. Adapter 3 (enp0s9) – 192.168.3.0/24
• Each PVE hosts’ IP on each network roughly corresponds to its hostname:
  1. prox1 – 192.168.1.101, 192.168.2.1, 192.168.3.1
  2. prox2 – 192.168.1.102, 192.168.2.2, 192.168.3.2
  3. prox3 – 192.168.1.103, 192.168.2.3, 192.168.3.3

I have built this cluster a few times and my Ethernet adapter names (enp0s3, enp0s8, and enp0s9) have always been the same. That may be a product of all the cloning, so YMMV. Pay close attention here because this can get very confusing.

Open the network interface config file for each PVE host:

nano /etc/network/interfaces

You should see the entry for your first Ethernet adapter (the bridged adapter in VirtualBox), followed by the virtual machines' bridge interface with the static IP that you set when you installed Proxmox. This is a Proxmox virtual Ethernet adapter. The last two entries should be your two host only adapters, #2 and #3 in VirtualBox. These are the adapters that we need to modify. The file for prox1 probably looks like this:

nano /etc/network/interfaces

auto lo
iface lo inet loopback

iface enp0s3 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.1.101
        netmask 255.255.255.0
        gateway 192.168.1.1
        bridge_ports enp0s3
        bridge_stp off
        bridge_fd 0

iface enp0s8 inet manual

iface enp0s9 inet manual

Ignore the entries for lo, enp0s3, and vmbr0. Delete the last two entries (enp0s8 and enp0s9) and replace them with this:

#cluster network
auto enp0s8
iface enp0s8 inet static
        address 192.168.2.1
        netmask 255.255.255.0
#migration network
auto enp0s9
iface enp0s9 inet static
        address 192.168.3.1
        netmask 255.255.255.0

Now repeat the process for prox2 and prox3, changing the last octet for the IP's to .2 and .3 respectively. When you are finished your nodes should be configured like so:

1. prox1 - 192.168.1.101, 192.168.2.1, 192.168.3.1
2. prox2 - 192.168.1.102, 192.168.2.2, 192.168.3.2
3. prox3 - 192.168.1.103, 192.168.2.3, 192.168.3.3

Save your changes on each node. Then reboot each one:

shutdown -r now

Network Testing
When your PVE hosts are booted back up, SSH into them again. Have each host ping every other host IP to make sure everything is working:

ping -c 4 192.168.2.1;\
ping -c 4 192.168.2.2;\
ping -c 4 192.168.2.3;\
ping -c 4 192.168.3.1;\
ping -c 4 192.168.3.2;\
ping -c 4 192.168.3.3

The result should be 4 replies from each IP on each host with no packet loss. I am aware that each host is pinging itself twice. But you have to admit it look pretty bad ass.

Once you can hit all of your IP's successfully, now it's time to make sure that multicast is working properly. This isn't a big deal in VirtualBox because the virtual switches are configured to handle multicast correctly, but it's important to see the test run so you can do it on real hardware in the future.

First send a bunch of multicast traffic at once:

omping -c 10000 -i 0.001 -F -q 192.168.2.1 192.168.2.2 192.168.2.3

You should see a result that is 10000 sent with 0% loss. Like so:

192.168.2.1 :   unicast, xmt/rcv/%loss = 9406/9395/0%, min/avg/max/std-dev = 0.085/0.980/15.200/1.940
192.168.2.1 : multicast, xmt/rcv/%loss = 9406/9395/0%, min/avg/max/std-dev = 0.172/1.100/15.975/1.975
192.168.2.2 :   unicast, xmt/rcv/%loss = 10000/9991/0%, min/avg/max/std-dev = 0.091/1.669/40.480/3.777
192.168.2.2 : multicast, xmt/rcv/%loss = 10000/9991/0%, min/avg/max/std-dev = 0.173/1.802/40.590/3.794

Then send a sustained stream of multicast traffic for a few minutes:

omping -c 600 -i 1 -q 192.168.2.1 192.168.2.2 192.168.2.3

Let this test run for a few minutes. Then cancel it with CTRL+C.

The result should again be 0% loss, like so:

root@prox1:~# omping -c 600 -i 1 -q 192.168.2.1 192.168.2.2 192.168.2.3
192.168.2.2 : waiting for response msg
192.168.2.3 : waiting for response msg
192.168.2.3 : joined (S,G) = (*, 232.43.211.234), pinging
192.168.2.2 : joined (S,G) = (*, 232.43.211.234), pinging
^C
192.168.2.2 :   unicast, xmt/rcv/%loss = 208/208/0%, min/avg/max/std-dev = 0.236/1.488/6.552/1.000
192.168.2.2 : multicast, xmt/rcv/%loss = 208/208/0%, min/avg/max/std-dev = 0.338/2.022/7.157/1.198
192.168.2.3 :   unicast, xmt/rcv/%loss = 208/208/0%, min/avg/max/std-dev = 0.168/1.292/7.576/0.905
192.168.2.3 : multicast, xmt/rcv/%loss = 208/208/0%, min/avg/max/std-dev = 0.301/1.791/8.044/1.092

Now that your cluster network is up and running, you can finally build your cluster. Up to this point, you have been entering identical commands into a SSH sessions. At this point, you can stop using the multi-exec feature of your SSH client.

First, create the initial cluster node on Prox1, like so:

root@prox1:~# pvecm create TestCluster --ring0_addr 192.168.2.1 --bindnet0_addr 192.168.2.0

Then join Prox2 to the new cluster:

root@prox2:~# pvecm add 192.168.2.1 --ring0_addr 192.168.2.2

Followed by Prox3:

root@prox3:~# pvecm add 192.168.2.1 --ring0_addr 192.168.2.3

One final configuration on Prox1 is to set the third network interface as the dedicated migration network by updating the datacenter.cfg file, like so:

root@prox1:~# nano /etc/pve/datacenter.cfg

keyboard: en-us
migration: secure,network=192.168.3.0/24

Now that the cluster is set up, you can log out of your SSH sessions and switch to the web GUI. When you open the web GUI for Prox1 (https://192.168.1.101:8006) and you should see all 3 nodes in your TestCluster:

Now you can manage all of your PVE Hosts from one graphical interface. You can also do cool shit like migrating VMs from one host to another, but before we can do that we need to set up some PVEVMs. There are more things to set up, but to see them in action, we need to build a couple of PVEVMS to work with, which I will cover in the next installment: Building PVE Containers.

Building a Proxmox Test Cluster in VirtualBox Part 2: Configuring the Hosts

In the last installment of this series, I discussed setting up the Proxmox VE hosts in VirtualBox. At this stage in the exercise there should be 3 VirtualBox VMs (VBVMs) running, in headless mode. These VBVMs should be running Proxmox VE, ready to host their own VMs (PVEVMs).

Before you can set up the cluster, storage replication, and high availability, you need to do a bit of housekeeping on your hosts. In this post, I will go over those steps making sure that the hosts are up to date OS wise and that your storage is properly configured for later use. Most of these steps can be accomplished via the Web UI, but using SSH will be faster and more accurate. Especially when you use an SSH client like SuperPuTTY or MobaXTerm that lets you type and paste into multiple terminals at the same time.

Log in as root@ip-address for each PVE node. In the previous post, the IPs I chose were 192.168.1.101, 192.168.1.102, and 192.168.1.103.

I don’t want to bog this post down with a bunch of Stupid SSH Tricks, so just spend a few minutes getting acquainted with MobaXTerm and thank me later. The examples below will work in a single SSH session, but you will have to paste them into 3 different windows like a peasant, instead of feeling like some kind of superhacker:

Step 1 – Fix The Subscription Thing

No, not the nag screen that pops up when you log into the web UI, I mean the errors that you get when you try to update a PVE host with the enterprise repos enabled.

All you have to do is modify a secondary sources.list file. Open it with your editor, comment out the first line and add the second line:

nano  /etc/apt/sources.list.d/pve-enterprise.list

# old and busted
#deb https://enterprise.proxmox.com/debian/pve stretch pve-enterprise

# new hotness
deb http://download.proxmox.com/debian/pve stretch pve-no-subscription

Save the file, and run your updates:

apt-get update; apt-get -y upgrade

While you are logged in to all 3 hosts, you might as well update the list of available Linux Container templates:

pveam update

Finally, if you set up your virtual disk files correctly according to the last post, you can set up your ZFS disk pool:

1. List your available disks, hopefully you see two 64GB volumes that aren’t in use on /dev/sdb and /dev/sdc:

   
   root@prox1:~# lsblk
   NAME               MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
   sda                  8:0    0   32G  0 disk
   ├─sda1               8:1    0 1007K  0 part
   ├─sda2               8:2    0  512M  0 part
   └─sda3               8:3    0 31.5G  0 part
     ├─pve-swap       253:0    0  3.9G  0 lvm  [SWAP]
     ├─pve-root       253:1    0  7.8G  0 lvm  /
     ├─pve-data_tmeta 253:2    0    1G  0 lvm
     │ └─pve-data     253:4    0   14G  0 lvm
     └─pve-data_tdata 253:3    0   14G  0 lvm
       └─pve-data     253:4    0   14G  0 lvm
   sdb                  8:16   0   64G  0 disk
   sdc                  8:32   0   64G  0 disk
   sr0                 11:0    1  642M  0 rom
   root@prox1:~#
   

   Assuming you see those two disks, and they are in fact ‘sdb’ and ‘sdc’ then you can create your zpool. Which you can think of as a kind of software RAID array. There’s waaaay more to it than that, but that’s another post for another day when I know more about ZFS. For this exercise, I wanted to make a simulated RAID1 array, for “redundancy.” Set up the drives in a pool like so:

   
   zpool create -f -o ashift=12 z-store mirror sdb sdc
   zfs set compression=lz4 z-store
   zfs create z-store/vmdata
   

   In a later post we will use the zpool on each host for Storage Replication. The PVEVM files for each of your guest machines will copy themselves to the other hosts at regular intervals so when you migrate a guest from one node to another it won’t take long. This feature pairs very well with High Availability, where your cluster can determine if a node is down and spin up PVEVMs that are offline.

   Now that your disks are configured, it’s time to move on to Part 3: Building The Cluster.

Building a Proxmox Test Cluster in VirtualBox Part 1: Building The Hosts

In my last post, I set the stage for why I built the virtualbox cluster, and now it it time to discuss the how.

In researching the best way to design a network for a Proxmox cluster, the bare minimum is one network connection. This one link does the following:

1. Hosts the web server for the management GUI – The web UI is pretty slick, and it’s great for viewing stats and checking for errors.
2. Hosts the network bridge for guest VMs – This bridge acts as a kind of virtual network switch for your PVEVMs to talk to the outside world.
3. Connects the host to the Internet – The PVE host needs to download security updates, Linux container templates, and install packages.

This one network interface is sort of the lifeline for a Proxmox host. It would be a shame if that link got bombed by incessant network traffic. As I discovered (the hard way) one possible source of incessant network traffic is the cluster communication heartbeat. Obviously, that traffic needs to go on its own network segment. Normally, that would be a VLAN or something, but I have some little dumb switches and the nodes have some old quad port NICs, so I wanted to just assign an IP to one port, and plug that port into a switch that is physically isolated from “my” network.

Once a cluster is working, migrating machines happens over the cluster network link. This is OK, but if your cluster network happens to suck (like when some jackass plugs it into a 10 year old switch) it can cause problems with determining if all the cluster nodes are online. So, now I want to set up an additional interface for VM migration. Migration seems like the kind of thing that happens only occasionally, but when you enable Storage Replication, the nodes are copying data every 15 minutes. Constant cluster chatter, plus constant file synchronization, has the potential to saturate a single network link. This gets even worse when you add High Availability, and there is a constant vote on if a PVEVM is up and running, followed by a scramble to get it going on another node.

So, at minimum we will need 3 network interfaces for the test cluster on VirtualBox. I didn’t want to spend a lot of time tinkering with firewall and NAS appliances, so I am leaving the “Prox management on its own network segment” and the “Dedicated network storage segment” discussions out of this exercise. I can’t decide if the management interface for my physical Proxmox cluster should sit on my internal network, or on its own segment. For this exercise, the management interface is going to sit on the internal network. My Synology NAS has 4 network ports, so I am definitely going to dedicate a network segment for the cluster to talk to the NAS, but that won’t be a part of this exercise.

[Virtual] Hardware Mode(tm)

Once you are booted up and VirtualBox is running, you can start building your VBVMs. I recommend building one VBVM to use as a template and then cloning it 3 times. I found that I kept missing important things and having to start over, so better to fix the master and then destroy the clones.

I called my master image “proxZZ” so it showed up last in the list of VBVMs. I also never actually started up the master image, so it was always powered off and the ZZ’s made it look like it was sleeping.

Create proxZZ with the following:

• First, make sure that you have created 2 additional Host Only Network Adapters in VirtualBox. In this exercise you will only use two, but it can get confusing when you are trying to match en0s9 to something, so do yourself a favor and make three. Make sure to disable the DHCP server on both adapters.



• Create a new virtual machine with the following characteristics :
  1. Name: ProxZZ
  2. Type: Linux
  3. Version: Debian 64bit (Proxmox is Debian under the hood.)
  4. Memory Size: 2048MB
  5. Hard drive: dynamically allocated, 32GB in size.
• Make sure that you have created 3 total virtual hard disks as follows:
  1. SATA0: 32GB. This will be your boot drive and system disk. This is where Proxmox PVE will be installed. Static disks are supposed to be faster, but this isn’t even remotely about speed. My laptop has a 240gb SSD, so I don’t have a ton of space to waste.
  2. SATA1: 64GB, dynamically allocated. This will be one of your ZFS volumes.
  3. SATA2: 64GB, dynamically allocated. This will be your other ZFS volume. Together they will make a RAID1 array.
• WHile you are in the storage tab, make sure to mount the Proxmox installer ISO
• Make sure that you have created 3 network interfaces as follows:
  1. Adapter 1: Bridged Network – this will be your management interface.
  2. Adapter 2: Host Only Network Adapter #2 – this will be your cluster interface.
  3. Adapter 3: Host Only Network Adapter #3 – this will be your VM migration interface.
  4. You may be tempted to do something clever like unplugging virtual cables or something. Don’t. You will be cloning this machine in a minute and you will have a hard time keeping all of this straight.
• Before you finish, make sure that the machine is set to boot from the hard drive first, followed by the CD/Optical drive. This seems stupid, but you will be booting these things in headless mode, and forgetting to eject the virtual CD rom is super annoying. So fix it here and stop being bothered with it.

When it’s done, it should look something like this:

Once you are sure your source VM is in good shape, make 3 clones of it. Don’t install Proxmox yet. SSH keys and stuff will play a major role in this exercise later, and I am not sure if VirtualBox is smart enough to re-create them when you clone it. I ran into this a few times so just clone the powered off VBVM. I called the clones prox1, prox2, and prox3.

[Virtual] Software Mode(tm)

Now it is time to start your 3 clones. This can get pretty repetitive, especially if you start the process over a couple of times. While you will appreciate cloning the servers, there isn’t really a simple way that I have discovered to mass produce the PVE hosts. In a few iterations of this exercise, I misnamed one of the nodes (like pro1 or prx2) and it’s super annoying later when you get the cluster set up and see one of the nodes named wrong. There is a procedure to fix the node name after you build it, but seriously just take your time and pay attention.

When you first start the install you will probably see an error about KVM Virtualization not being detected. Which should be impossible, right? The PVE host is *literally* a virtual machine. This is probably VBox for Windows not passing something to PVE Linux, or VBox misidentifying your CPU. Whatever it is, this isn’t a showstopper because our test systems that will run on the PVE cluster aren’t going to be VMs, they’ll be Linux Containers, but in the interest of not making my head hurt I am still going to call them VMs. The PVE hosts are VirtualBox VMs, and the Linux Containers running on Proxmox are Proxmox VE VMs. VBVMs are VMs running under VirtualBox, PVEVMs are Linux Containers running under Proxmox VE. *whew*

As you do the install, select your 32gb boot drive and configure your IP addresses.
I went with a sequence based on the hostname:
prox1 – 192.168.1.101
prox2 – 192.168.1.102
prox3 – 192.168.1.103
Like I said before, go slowly and pay attention. This part is super repetitive and it’s easy to make a stupid mistake that you have to troubleshoot later. At some point, I guarantee that you will give up, destroy the clones, and start over 🙂

Send In The Clones

Once your hosts are installed, it’s time to shut them down and boot them again, this time in headless mode. This is where fixing the boot order on ProxZZ pays off. With all 3 VBVMs are started up, you are ready for the next stage of the exercise: installing your PVE hosts.