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Best Practices and Recommendations

Use the latest version of CloudBacko Pro

Install the latest version of CloudBacko Pro on the staging machine or Backup Client Computer for backup of VM hosted on a VMware ESX/ESXi server, or on the vCenter server.

Install CloudBacko Pro on a physical staging machine

For best backup and restore performance, it is highly recommended that CloudBacko Pro is installed on a server grade staging machine or backup client computer with sufficient memory and processing power. As guest VM can be very large, during backups and restore this may involve the compression & encryption of large amounts of data, which can be very resource intensive.

VMware Tools

Make sure the latest version of VMware Tools is installed on each guest VM selected for backup. VMware Tools is used by CloudBacko Pro to quiesce the guest VMs prior to backing them up to create consistent backup for your VMs.

Quiescing is a process that ensures that the disk data is in a state suitable for backups to reduce the possibility of data corruption upon restore. This is especially important for transaction-based applications running on VMs like MS SQL Server, MS Exchange etc. There are different types of quiescing mechanisms, according to the guest operating systems (e.g. Crash-consistent, File-system-consistent and Application-consistent quiescing).

Do not use a guest VM as a staging machine

Although installing CloudBacko Pro on a guest VM as a staging machine is possible, the backup and restore will work as on a physical staging machine. This setup is actually inefficient and can lead to possible performance bottlenecks on the VMware host server, as in a VMware host the virtualization layer separates guest VM OS layer and the VMware host physical hardware layer.

As the guest VM operating system does not have direct access to physical hardware where the data resides, a backup agent installed inside the guest VM must go through the virtualization layer to access the guest virtual machine data.

Use the VDDK backup mode / CBT feature

The CBT (Change Block Tracking) feature, which is required for backup in VDDK mode, is supported by VM host with VMware Essentials License (or other paid licenses). The CBT feature, which is utilized for tracking changes of data blocks since the last backup can be done quickly and directly on the VM host. Therefore, the performance of incremental backups is much faster with VDDK backup mode.

Another advantage of VDDK mode is the amount of data backed up is relatively smaller. The used data size of the guest VM is backed up instead of the provisioned size, so the storage cost of these backups will be less.

Local temporary directory

The temporary directory of a VMware VM backup set is set to a local volume, and not to a network volume (e.g. to improve I/O performance).

However, the temporary directory should not be set to the system volume (e.g. where the operating system is installed).

Well planned backup schedule

Plan your backup schedules carefully to minimize any performance impact on the VMware host.

To avoid concentrated disk I/O on the VMware host datastores which will have a negative performance impact on the guest VMs residing on these datastores, you should schedule your backups to limit the number of concurrent VM backups on a host and shared datastores. Hosts typically share the same datastores in virtual environments, and bottlenecks caused by too many simultaneous VM backups on a single datastore will affect all hosts that have VMs running on that datastore.

Backup the guest VMs to more than one destination

To provide maximum data protection and recovery flexibility you should consider to store your guest VM backups in multiple backup destinations, ideally both onsite and offsite locations. Onsite locations on local or network drives will enable very quick recovery even for large guest VMs. While offsite locations will ensure that if there is a site outage, the guest can be restored from another location.

Increase Java memory

Consider to increase the Java memory allocation setting for CloudBacko Pro (Java heap space) if you are using non-VDDK backup mode.

If you are using non-VDDK mode and or Granular restore, it is recommended to increase the Java heap size space to at least 2GB or above for optimal performance.

Refer to this article for further instruction:


  • It is highly recommended to backup the whole VM instead of individual disk for backup of virtual machine with snapshot.
  • Consider to perform routine recovery test to ensure your backup is setup and performed properly.
  • Consider to disable the memory snapshot or quiesce guest options when taking snapshot for VMware VM backup, to shorten the time required for the process.
    • Snapshot the virtual machine's memory
    • Quiesce guest file system (Needs VMware Tools installed)
public/module/vmware/best_practices.txt · Last modified: 2019/09/19 16:07 by ronnie.chan