Periodically taking snapshots of your VMware ESXi virtual machine state is essential to ensuring you can revert problematic application upgrades and quickly correct other issues. However, allowing VMware snapshot files to accumulate without proper oversight can profoundly degrade virtual machine performance. In fact, if you storage runs out of free disk space, your virtual machines might not be able to even start, let alone run at peak performance. Therefore, to mitigate problems that could threaten the availability or integrity of your data, you need proper VMware snapshot management.

VMware snapshots basics

A VMware snapshot is a copy of the state of a virtual machine disk file (VMDK) at a given moment in time, taken by the vSphere Client Snapshot Manager. Snapshots provide a change log (delta) for the virtual disk, and are used to restore a virtual machine back to a previous state. Here’s what you need know about how VMware snapshots work:

  • You can take multiple snapshots of a virtual machine, including its memory, to create multiple state-in-time restore points. This strategy increases the resiliency of your infrastructure.
  • However, snapshot files take up disk space, so you need to control snapshot creation and deletion to make sure that there is enough free space on your storage for your production needs.
  • When you create a snapshot, the only thing that happens is some metadata changes, which occur pretty much instantly. From that point on, in order not to change anything on the disk and thereby ensure the snapshot remains useful, any changes to the file system get associated with the current live file system; the disk structures associated with the snapshot are left untouched. This is done using a technique called “copy on write.”

Better VMware snapshot management with actionable reports and alerts from Netwrix

VMware Snapshot Manager provides only limited snapshot management functionality: You can see the snapshots of only one virtual machine at a time, and to get the detailed information you need to manage snapshots (such as snapshot size or disk space requirements), you have to go to the storage. Therefore, while VMware Snapshot Manager is useful, it may not be sufficient to enable you to get the control VMware snapshot creation across all of your virtual machines that you need to minimize memory, storage and performance risks.

Netwrix Auditor for VMware enables you to manage your snapshots more efficiently by providing an actionable VMware snapshot report and proactive alerts. You can:

  • Gain complete visibility into all changes across all of your virtual machines, including snapshot creation, modification and deletion.
  • Avoid downtime by quickly spotting snapshot creations and knowing immediately who made each snapshot, when it was created, and on which machine it was made.
  • Get alerts on suspicious snapshot deletions and other aberrant activity so you can respond immediately.
  • Easily stay informed about snapshot activity by having the change report delivered automatically on the schedule you specify.

VMware Snapshot Changes report from Netwrix Auditor, with actionable What, Who and When details

VMware Snapshot Changes report from Netwrix Auditor: What, Who and When