Hyper-V Summary

1, Hyper v virtual hard drive type and difference

Fixed-size hard disk: a fixed-size virtual hard disk is a. vhd or. vhdx file that is determined when the file is created. The size of the. vhd or. vhdx file remains the same even if the amount of data stored in the file has changed. Fixed hard disk size hard drive can provide better performance.

Dynamic extended hard disk: a virtual hard disk that dynamically expands the virtual hard disk with the growth. is the default type of virtual hard disk that is created by the Hyper-V host. The size of any dynamically expanding hard drive will only grow without shrinking. You can reduce the size of the hard drive by dynamically expanding it only by compressing it.

differencing hard disk: A differencing virtual hard disk is a virtual hard disk that is associated with a "parent-child" relationship with another virtual hard disk. The differencing virtual hard disk is a child, and the associated virtual hard disk is the parent. The parent hard disk can be a "fixed size" hard disk or a "dynamically extended" hard disk. The differencing virtual hard disk (child) stores only all change records made to the parent hard disk and provides a way to save changes without altering the parent hard disk.

2. The difference between VHD and VHDX

The maximum capacity of a VHD virtual hard disk is 2TB,VHDX virtual hard disk with a maximum capacity of 64TB. However, the virtual hard disk attached to the IDE controller cannot exceed 127GB. To support larger virtual hard disk capacity, it is recommended that you attach the virtual hard disk to the SCSI adapter. The performance of the VHDX is better than the VHD.

3, Hyper v replication time interval

Only one copy of content is supported every 5 minutes in a Windows Server 2012 environment and is supported every 30 seconds, every 5 minutes, and every 15 minutes in the Windows Server R2 environment. This means that if the data is not replicated within the specified time interval and the primary virtual machine is down, it means that the app will lose data. Application-consistent snapshots are created once per hour and then replicated to the replica virtual machine based on the time interval that has been set.

4. Precautions for deploying a heartbeat network

A. When setting the heartbeat network IP address, only the IP address and subnet mask are set, and the DNS parameters and default gateway do not need to be set

B. The heartbeat network and the external network are not in the same IP address segment

c. When setting network card properties, be aware that the "Disable NetBIOS on TCP/IP" option is enabled

5. Problems with snapshots

A. Unable to restore the specified target file

B. Consuming excessive disk space

C. Increase system load

D. If the snapshot file is too large, it will take a while for the merge to complete, and the external access functionality will not be available during the merge. It is recommended that delete snapshots be completed during non-working hours.

E. Snapshots are not a substitute for backups

F. When a snapshot is deleted, space is not immediately released

G. Snapshots are files with the suffix. Avhd or. AVHDX, and by default the snapshot files are in the same folder as the virtual hard disk. Therefore, disk IO performance determines the performance of the snapshot file. It is recommended that snapshot files and virtual machine hard disk files be deployed on separate physical disks to enhance read and write performance, thereby increasing the efficiency of virtual machines. The snapshot file location can be adjusted with "hyper-V".

6. Implementing Hyper-V Manager to manage multiple Hyper-V hosts

A. Open Active directory Users and Computers, and select the Computers option.

B. Select the target computer that requires permissions, right-click Properties, and tap delegation.

C. Select "Trust this computer only to delegate specified services"--"use Kerberos only", click "Add", select the computer to which you want to add permissions, click "OK", add "CIFS" and "Microsoft Virtual System Migration Service ".

7. No sharing environment real-time migration prerequisites and advantages

Prerequisites:

A.hyper-v host must be a Windows Server2012 system

B.hyper-v host must be joined to Active Directory, identity is a member server

C.HYPER-V Host physical Processor (CPU) must be a product of the same manufacturer, but allows different versions to be used

D. If you are migrating multiple Hyper-V hosts in the same Hyper-V Manager, you must configure permission delegation for the source host if you are performing a passive migration.

E. Secure and reliable network connection.

Advantages:

A. Ensure that at least one virtual machine is available when a failure occurs during migration that causes the migration to fail

B. Support for migrating virtual machines across clusters, such as migrating from a non-clustered Hyper-V host to a clustered Hyper-V host

C. Migrating virtual machines that support different storage types are not constrained by storage type (SAN, Icssi, DAS, NAS), enabling real-time migration

D. Support for PowerShell scripts

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Hyper-V Summary