What is VMware SnapShot? VMware Snapshot Management

VMware Snapshot'lari, vSphere It provides administrators with the ability to instantly record the state of virtual machines at a specific point in time. This feature is very useful for reverting changes and protecting critical data during development and testing processes. In this article, VMware SnapshotHow to manage and vSphere We will examine the best practices for effective use of this feature in the environment.

What is VMware Snapshot?

"SnapshotThe concept of “snapshot” often conjures up images of a snapshot taken with a camera; an image captured at a specific moment in time. VMware Snapshot The function works on a similar principle: It records the entire state of a running virtual machine at that exact moment, including its memory contents and virtual machine settings. This feature is especially great for critical operations such as system updates or new software installations.

VMware Snapshot Advantages

VMware Snapshot's are particularly useful in development and test environments. Ideal for a variety of use cases, this feature supports business continuity by enabling rapid restore. Here are some common use cases:

  • Code Changes: Deploying new code to development servers.
  • Operating System Updates: Installing important updates.
  • Driver Updates: Updating or updating hardware drivers.
  • Software Upgrades: Migration to new versions of installed software.
  • New Software Installations: Adding new applications to servers.
  • Forensic medicine: Recording system status after suspicious or malicious activity.
  • Power Status: Preserving the power state of the virtual machine when the snapshot is taken.
  • VM Settings and Hardware Capture: Provides a safety net for fallback when numerous settings changes are made.

VMware Snapshot Architecture

VMware SnapshotThe infrastructure of 's consists of a set of files that make it possible to roll back changes made to virtual machines:

  • .vmdk and -delta.vmdk: These files allow for rollback of snapshots and data changes made. Snapshott's can be built on top of each other, creating a chain of snapshots containing the changes.
  • .vmsd: VMware A type of database file that contains snapshot information and defines the connections between disks associated with the snapshot.
  • Snapshot.vmsn: This file records the active memory status of the virtual machine and shows the current state of the memory VMAllows you to take a snapshot of the . When the memory state is saved, this process takes longer than when the memory is not saved.

VMware Snapshot's provide flexibility and security when managing your virtual environments. However, it is important to plan your use of snapshots carefully as they can impact performance and storage space.

vmware snapshot cengizyilmaz

Best Practices for VMware Snapshot

VMware SnapshotAlthough they offer many useful features, they may not be suitable for every situation or every use case. Here are VMware SnapshotHere are some important things to consider when using :

  1. Not Using Snapshots as Backups:
    • VMware As emphasized by, Snapshot'are not intended to be a complete copy of your data. They are dependent on the VM's underlying disks and are useless without them. "Delta" disks do not provide a complete data set.
  2. Number of Snapshots:
    • There is a maximum of 32 Snapshots supported in a virtual machine, but to optimize performance it is generally recommended to use no more than 2 or 3 Snapshots. Too many Snapshots can significantly degrade system performance.
  3. Snapshot Duration:
    • Snapshots should not be left active for more than 72 hours. Snapshots left unattended for long periods of time will continue to grow and potentially fill up storage space.
  4. Snapshot and Data Protection:
    • Data protection solutions can use Snapshots until the backup iteration is complete. Once the backup process is complete, it is important to properly purge Snapshots from the virtual machine.
  5. Preventing Virtual Disk Changes:
    • While there is an active Snapshot, any changes made to virtual disks are blocked. This includes expanding the size of the virtual disk.

Finding Working Snapshot Files with PowerCLI

PowerCLI, VMware vSphereActive in SnapshotIt is a powerful tool for managing . The following commands can be used to find all active Snapshots in a single VM or multiple VMs:

get-vm <vm name> | get-snapshot

For all VMs in a specific folder:

get-vm -location | get-snapshot | fl

Creating a Snapshot with vSphere Client

Snapshot creation can be easily accomplished using the VMware vSphere Client GUI or PowerCLI. Using the vSphere Client, you can easily take a snapshot by right-clicking on a virtual machine and selecting “Snapshot > Take Snapshot”.

These best practices and guidelines will help you manage your VMware Snapshots more effectively and avoid unnecessary resource consumption in your virtual environment.

creating a snapshot vsphere

Other options available to you when taking a snapshot include:

  • Include VM Memory: This option also includes the memory state of the virtual machine in the Snapshot. It captures the exact current state of active applications and processes so that the virtual machine continues in the same operating state when the Snapshot is restored. Memory Snapshots can be especially important for applications that process dynamic data.
  • Silent Guest File System (Requires VM Tools): This option “mutes” the virtual machine’s file system. Muting ensures that the virtual machine’s file system is organized in a way that maintains file consistency during backup operations. This is critical for applications that often host constantly changing data, such as databases. A muted file system ensures that backups are reliable and consistent.

These options, Snapshot should be evaluated depending on the needs and workload of your virtual machine.

For example, if you are running a process-intensive application and want it to resume quickly when a full restore is required, enabling the “Include VM Memory” option may be a good choice. For backup purposes, it is recommended to enable the “Silent Guest File System” option.

the take snapshot dialog box in the vsphere client

Taking VMware Snapshots with PowerCLI

The vSphere Client GUI is a great tool for creating temporary or one-time VMware Snapshots, ideal for individual virtual machines. However, when you want to take bulk Snapshots across multiple virtual machines, PowerCLI greatly simplifies this process. PowerCLI simplifies snapshot management by letting you interact with your vSphere environment.

Taking Snapshots for Single and Multiple Virtual Machines

For a single virtual machine Snapshot to get below PowerCLI You can use the command:

get-vm <vm name> | new-snapshot -Memory -quiesce -name "testSnapshot"

If you want to create snapshots in bulk across multiple virtual machines, you can use the following command for all VMs in a specific folder:

get-vm -location "folderName" | new-snapshot -Memory -quiesce -name "batchSnapshot"

These commands allow you to create snapshots across multiple virtual machines to support your workload and operational requirements.

Snapshot Management, Restoration and Deletion

PowerCLI ayrıca SnapshotIt can also be used to manage, restore and delete 's. All the virtual machines SnapshotThe following command can be used to view and manage 's:

get-vm <vm name> | get-snapshot | select Name, Created, SizeMB

To revert to the last snapshot on a virtual machine:

get-vm | get-snapshot | sort Created -Descending | select -First 1 | set-vm -confirm:$false

To delete all Snapshots and return the virtual machine to its original state:

get-vm | get-snapshot | remove-snapshot -confirm:$false

These operations, VMware It provides efficient resource management in your environment and allows you to quickly restore when necessary.

Creating Snapshot with vSphere Client GUI

vSphere Client GUI, located in your virtual machines VMware SnapshotIt provides an intuitive interface for managing virtual machines. Right-click on a virtual machine and select “Snapshot > Take SnapshotYou can easily create a snapshot by selecting the “ ” option. This interface is useful for users who want to manage Snapshots visually.

PowerCLI and vSphere Client GUI, VMware flexible and powerful in your environment Snapshot are two primary tools for managing your system, and while each serves different needs, PowerCLI is particularly valuable for batch processing and automation.

managing vmware snapshots using the vsphere client


Delete a Specific Snapshot from Multiple Virtual Machines with PowerCLI

VMware Deleting a specific Snapshot across multiple VMs in your environment can be important, especially for routine maintenance and resource management. Here is an example PowerCLI script that you can use to delete Snapshots by a specific Snapshot name from all VMs in a specific folder:

$vms = Get-VM -Location "folderName"
$snapshotName = "MySnapshotName"

foreach ($vm in $vms) {
    $snapshot = Get-Snapshot -VM $vm -Name $snapshotName
    Remove-Snapshot -Snapshot $snapshot -RunAsync -Confirm:$false
}

This script loops through all virtual machines in the specified folder, finds the Snapshot with the specified name for each VM, and deletes it. -RunAsync parameter ensures that the operation occurs asynchronously, so the command does not have to wait for the previous operation to complete before moving on to the next virtual machine.

Points to Consider When Deleting Snapshots

Important points to note when removing a Snapshot in VMware vSphere:

  1. Other Virtual Machine Operations:
    • During snapshot deletion, you cannot perform any other operations on the virtual machine. This means that the virtual machine is closed to other management and maintenance operations.
  2. Consolidation Process:
    • When deleting a large snapshot, a process of merging the delta disk to the base disk occurs. Until this process is complete, the virtual machine may become unresponsive because it will “stun/freeze”.
  3. Stun/Freeze Times:
    • Stun/freeze operation occurs due to changes written from delta disks to the base disk. I / O Consolidation times may be longer and stun times may increase for VMs under operations. ESXiIf the stun duration exceeds 15 seconds, it will continue to try the process for 10 iterations. If it fails on the 10th iteration, it will stop the process and the Snapshot will not be deleted.

This information is available in your VMware environment. Snapshot can help you understand the situations and potential challenges you may encounter during snapshot management. Automating your snapshot management process using PowerCLI scripts saves time and reduces the error rate.


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