"WMware" Server capacity expansion for VMware Server virtualization Management

Abstract server physical resources into logical resources, so that a server into a few or even hundreds of isolated virtual servers, we are no longer limited by the physical boundaries, but the CPU, memory, disk, I/O and other hardware into a dynamically managed "resource pool", thereby improving resource utilization, simplifying system management, Implement server consolidation to make it more resilient to business change--------this is server virtualization. Server virtualization solves issues related to server sprawl, resource consumption, server sprawl, energy consumption, and high availability.

When you deploy a server within a VMware virtual machine, you need to configure a variety of hardware in a virtual configuration, where the format has three choices when configuring the hard disk: thick-provisioned delay zero, thick provisioning zero, thin provisioning.

1, thick provision delay 0 (zeroed thick)

Creates a virtual disk in the default thick format. Allocate the required space for the virtual disk during the creation process. Any data that is persisted on the physical device is not erased on creation, but it is zeroed as needed when the first write operation is performed from the virtual machine.

Simple is to allocate the space of the specified size immediately, the data in the space is not emptied, and then emptied as needed.

Advantages for disk performance is good, short time, suitable for the virtual Desktop pool mode.

2, thick provision 0 (eager zeroed thick)

Create thick disks that support clustering features, such as Fault tolerance. Allocate the required space for the virtual disk when it is created. In contrast to the flat format, the data retained on the physical device is zeroed during the creation process. It may take longer to create a disk of this format than to create another type of disk.

Simply put, allocate the space of the specified size immediately and empty all the data in that space.

Choosing this way of disk performance is the best, long time, suitable for running a heavy application business of virtual machines.

3. Thin provisioning (thin)

Use thin provisioning format. Initially, a thinly provisioned disk uses only the data storage space that the disk originally needed. If you later need more space for a thin disk, it can grow to the maximum capacity allocated for it.

The simplest is to specify the maximum space for the disk file to grow, and to check whether the limit is exceeded when it needs to grow.

So when there is an I/O operation, space must be allocated before the space is zeroed to perform I/O operations. Disk performance degrades when there are frequent I/O operations.

Disk performance is good when I/O is infrequent, and disk performance is poor when I/O is frequent. Short time, suitable for business application virtual machines that are not frequently disk I/O.

The difference between the three is that the thick-provisioned delay 0 and the thick-provisioned 0 are the first to allocate such a large amount of space, but the former is not clear about the spatial data, and the latter has been cleared at the beginning of the creation. The thin provisioning is to set the disk to a maximum space, and then the disk uses only the space the system originally needed, and its space will increase in use.

In general, when you format a disk, you often set it to thin provisioning (thin) to make full use of the virtual machine resources, but sometimes a problem occurs, but when the space used by the disk has been exhausted, the virtual machine does not give it much space, when there is not enough disk space to resolve it.

There are two types of solutions:

1. Add a new disk to it and mount it to a folder on the system.

2. Convert thin provisioning (thin) to thick provisioning, giving the space one time to disk, which also solves the problem of insufficient disk space.

"WMware" Server capacity expansion for VMware Server virtualization Management