Year: 2020

Disk Stripping – Optimize storage performance

Jovan Stosic May 11, 2020

Disks can be striped using a striping technology (such as Storage Spaces on Windows or mdadm on Linux) to increase the throughput and IOPS by spreading disk activity across multiple disks. Using disk striping allows you to really push the limits of performance for disks, and is often seen in high-performance database systems and other systems with intensive storage requirements.

https://docs.microsoft.com/en-us/learn/modules/design-for-performance-and-scalability-in-azure/4-optimize-storage-performance

Disk Stripping – Optimize storage performance was last modified: May 11th, 2020 by Jovan Stosic

Optimize storage performance – Premium Storage

Jovan Stosic May 11, 2020

Premium storage can attach only to specific virtual machine (VM) sizes. Premium storage capable sizes are designated with an “s” in the name, for example D2s_v3 or Standard_F2s_v2. Any virtual machine type (with or without an “s” in the name) can attach standard storage HDD or SSD drives.

https://docs.microsoft.com/en-us/learn/modules/design-for-performance-and-scalability-in-azure/4-optimize-storage-performance

Optimize storage performance – Premium Storage was last modified: May 11th, 2020 by Jovan Stosic

Virtualbox – Teleporting Virtual Machines

Jovan Stosic May 10, 2020

Oracle VM VirtualBox supports teleporting. Teleporting is moving a virtual machine over a network from one Oracle VM VirtualBox host to another, while the virtual machine is running. This works regardless of the host operating system that is running on the hosts. You can teleport virtual machines between Oracle Solaris and Mac OS X hosts, for example.

Teleporting requires that a machine be currently running on one host, which is called the source. The host to which the virtual machine will be teleported is called the target. The machine on the target is then configured to wait for the source to contact the target. The machine’s running state will then be transferred from the source to the target with minimal downtime.

Teleporting happens over any TCP/IP network. The source and the target only need to agree on a TCP/IP port which is specified in the teleporting settings.

At this time, there are a few prerequisites for this to work, as follows:

  • On the target host, you must configure a virtual machine in Oracle VM VirtualBox with exactly the same hardware settings as the machine on the source that you want to teleport. This does not apply to settings which are merely descriptive, such as the VM name, but obviously for teleporting to work, the target machine must have the same amount of memory and other hardware settings. Otherwise teleporting will fail with an error message.
  • The two virtual machines on the source and the target must share the same storage, hard disks as well as floppy disks and CD/DVD images. This means that they either use the same iSCSI targets or that the storage resides somewhere on the network and both hosts have access to it using NFS or SMB/CIFS.

    This also means that neither the source nor the target machine can have any snapshots.

To configure teleporting, perform the following steps:

  1. On the target host, configure the virtual machine to wait for a teleport request to arrive when it is started, instead of actually attempting to start the machine. This is done with the following VBoxManage command: 
    VBoxManage modifyvm targetvmname --teleporter on --teleporterport port

    targetvmname is the name of the virtual machine on the target host and port is a TCP/IP port number to be used on both the source and the target hosts. For example, use 6000. See Section 8.8, “VBoxManage modifyvm”.

  2. Start the VM on the target host. Instead of running, the VM shows a progress dialog, indicating that it is waiting for a teleport request to arrive.
  3. Start the VM on the source host as usual. When it is running and you want it to be teleported, issue the following command on the source host: 
    VBoxManage controlvm sourcevmname teleport --host targethost --port port

    where sourcevmname is the name of the virtual machine on the source host, which is the machine that is currently running. targethost is the host or IP name of the target host on which the machine is waiting for the teleport request, and port must be the same number as specified in the command on the target host. See Section 8.13, “VBoxManage controlvm”.

For testing, you can also teleport machines on the same host. In that case, use localhost as the hostname on both the source and the target host.

http://www.virtualbox.org/manual/ch07.html#teleporting

Virtualbox – Teleporting Virtual Machines was last modified: May 10th, 2020 by Jovan Stosic