So, you want to run your own hypervisor using xenserver, but you want to have some of the flexibility of KVM too. This instructional guide explains how to install and configure KVM with virt-manager and with X11 forwarding. We will go step by step. In this case I am using a mac.
Step 1 – Create Rackspace onmetalv2 server
In this case I’ll be using a 40 cpu 128GB machine as the host utilizing the new onmetalv2 server range offered by Rackspace public cloud.
Please note that this is a bare metal server, not a cloud server, however it is offered by the same cloud platform at mycloud.rackspace.co.uk
Step 2 – Install and configure KVM
sudo yum update -y sudo yum -y install kvm virt-manager libvirt virt-install qemu-kvm xauth dejavu-lgc-sans-fonts
Step 3 – Start and configure libvirtd
chkconfig libvirtd service libvirtd status service libvirtd restart service libvirtd status
Step 4 – MAC SYSTEMS – Install X Quartz
For mac users simply install X Quartz, which can be found at http://www.xquartz.org/
Step 4a – Windows Systems – Install Xming
Windows users can get in on the action too, using xming which can be found at https://sourceforge.net/projects/xming/
Step 5 – MAC SYSTEMS ONLY – Configure X11 Forwarding
Xming will work out of the box for windows, but for Mac users you need to make sure you have enabled X11 forwarding.
touch ~/.ssh/config echo "ForwardX11 yes" >> ~/.ssh/config
This simply allows X11 forwarding for Mac users which needs to be done at the client side. Then you can virtualize any application you like on the client, but running the application such as firefox , or even a virtual machine on the remote server. SSHv2 is beautiful. That’s it you’ve completed the most important steps.
Running virt-manager for the first time
[root@on-metal-test-2 ~]# virt-manager
After running the above command you will see something like the image below. You’ll see an X window open on your local client machine, which is associated with an application running on the remote server your connected to via SSH. This is pretty damn cool.
Lets take this further and install firefox to demonstrate how awesome this is!
yum install firefox -y
Now we’re using firefox thru ssh, much better and more convenient to use X11 forwarding for this, than using a proxy for instance on the client configured with tunnel or vpn.
Nice!
Lets take it a bit further and start installing xen server with KVM. I am very tempted to use ZFS for this since onmetal v2 has 2 1600GB disks…
Create partitions for KVM store
fdisk -l fdisk /dev/sdc # type m , then type n, then type p, enter, enter, enter, enter, then type w fdisk /dev/sdd # type m , then type n, then type p, enter, enter, enter, enter, then type w
Create filesystem for KVM store
[root@on-metal-test-2 ~]# mkfs.ext3 /dev/sdc1 && mkfs.ext3 /dev/sdd1 mke2fs 1.42.9 (28-Dec-2013) Discarding device blocks: done Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 97656832 inodes, 390624640 blocks 19531232 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 11921 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Allocating group tables: done Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done mke2fs 1.42.9 (28-Dec-2013) Discarding device blocks: done Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 97656832 inodes, 390624640 blocks 19531232 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 11921 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Allocating group tables: done Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done
Now we have created the filesystem. What about creating the ZFS partition. To do this we need to go thru a fairly laborious process (at least if you don’t know what your doing). As I discovered my yum installation wasn’t automatically providing the correct devel source for the kernel to use the ZFS DKMS module. As ZFS is really a native BSD package.
One of the problems I had was this
Loading new spl-0.6.5.6 DKMS files... Building for 3.10.0-327.10.1.el7.x86_64 Module build for kernel 3.10.0-327.10.1.el7.x86_64 was skipped since the kernel source for this kernel does not seem to be installed. Installing : zfs-dkms-0.6.5.6-1.el7.centos.noarch 4/6 Loading new zfs-0.6.5.6 DKMS files... Building for 3.10.0-327.10.1.el7.x86_64 Module build for kernel 3.10.0-327.10.1.el7.x86_64 was skipped since the kernel source for this kernel does not seem to be installed.
This can be checked out in more detail by running an;
yum search --show-duplicates kernel-devel # and rpm -qa | grep kernel
This gave me the right version of the devel kernel I needed to install ZFS to my current kernel with a module, as opposed to completely recompiling the whole thing. Nice!
Install ZFS and kernel devel
sudo yum localinstall --nogpgcheck http://archive.zfsonlinux.org/epel/zfs-release.el7.noarch.rpm sudo yum install epel-release sudo yum install zfs kernel-devel-3.10.0-327.10.1.el7.x86_64
Enable ZFS
[root@on-metal-test-2 adam]# /sbin/modprobe zfsCreate the 2 disk mirror using ZFS
[root@on-metal-test-2 adam]# zpool create -f kvmstore mirror sdc1 sdd1
Check KVM store disk
[root@on-metal-test-2 adam]# df -h Filesystem Size Used Avail Use% Mounted on /dev/md126p1 220G 2.3G 209G 2% / devtmpfs 63G 0 63G 0% /dev tmpfs 63G 0 63G 0% /dev/shm tmpfs 63G 26M 63G 1% /run tmpfs 63G 0 63G 0% /sys/fs/cgroup tmpfs 13G 4.0K 13G 1% /run/user/0 kvmstore 1.5T 0 1.5T 0% /kvmstore
Run Virt manager to create Xenserver VM
Now we’ve created our partition and filesystem and configured ZFS we can run the virtual machines off the new kvm partition store. simples
Click top left icon on corner to create new VM
Download the Xenserver ISO to /root of hypervisor
root@on-metal-test-2 ~]# wget http://downloadns.citrix.com.edgesuite.net/10175/XenServer-6.5.0-xenserver.org-install-cd.iso --2016-04-27 10:29:22-- http://downloadns.citrix.com.edgesuite.net/10175/XenServer-6.5.0-xenserver.org-install-cd.iso Resolving downloadns.citrix.com.edgesuite.net (downloadns.citrix.com.edgesuite.net)... 104.86.110.32, 104.86.110.49 Connecting to downloadns.citrix.com.edgesuite.net (downloadns.citrix.com.edgesuite.net)|104.86.110.32|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 603744256 (576M) [application/octet-stream] Saving to: ‘XenServer-6.5.0-xenserver.org-install-cd.iso’ 100%[====================================================================================================================================>] 603,744,256 17.6MB/s in 38s
Select Local Media (we’re going to use a Xenserver ISO)
Click browse, then press the bottom left + icon to add some pools. We’re going to add /root which has our iso in it, and we’re also going to add kvmstore aswell.
Congratulations you have now added the stores. Now all we need to do is finish configuring the VM.
We want to select the root partition now we have set up the pool, and choose the xenserver iso we just recently downloaded.
We are almost there now! Lets set the number of cpu and ram! Also lets make sure we use the kvmstore we just setup instead of the ‘main disk’ of the server.
Select our KVM store ‘pool’ on the left hand side, and then press + to add the kvmstore.qcow2 volume, see the images for illustration.
click choose volume at the bottom left to confirm! And finally name the server
awwww crap , we got this error because the libvirtd kvm configuration isnt running as root
This can be quickly resolved by editing the /etc/libvirt/qemu.conf and making sure user = “root” and group = “root” are present.
Job done!
