NetBackup™ for VMware Administrator's Guide
- Introduction
- Required tasks: overview
- Configuring RBAC roles for VMware administrators
- Notes and prerequisites
- VMware vSphere privileges
- Managing VMware servers
- About VMware discovery
- Add VMware servers
- Change resource limits for VMware resource types
- Configuring backup policies for VMware
- Backup options on the VMware tab
- Exclude disks tab
- Configuring a VMware Intelligent Policy
- About the Reuse VM selection query results option
- Use Accelerator to back up virtual machines
- Configuring protection plans for VMware
- Malware scan
- Instant access
- Instant rollback
- Continuous data protection
- Backing up virtual machines
- VM recovery
- VMware agentless restore
- Restoring Individual files and folders from VMware backups
- Using NetBackup to back up Cloud Director environments
- Recover VMware Cloud Director virtual machines
- Restore virtual machines with Instant Recovery
- Protecting VMs using hardware snapshots and replication
- Best practices and more information
- Troubleshooting VMware operations
- NetBackup logging for VMware
- Snapshot error encountered (status code 156)
- Appendix A. Configuring services for NFS on Windows
- About configuring services for NFS on Windows 2012 or 2016 (NetBackup for VMware)
- Appendix B. Backups of VMware raw devices (RDM)
Controlling full sync
When you subscribe a VM to a CDP-enabled protection plan, NetBackup initiates full sync, to get the entire data of the newly protected VM. For a newly subscribed VM, NetBackup does not have any data to apply the incremental backup features; hence full sync is initiated. During a full sync, NetBackup captures the entire data of the VM, from the underlying VMDKs to the CDP staging location, and subsequently to the NetBackup STUs.
Full sync is normally triggered when you subscribe a new VM to a CDP-enabled protection plan, but in certain scenarios, you can manually initiate a full sync:
Accidental corruption or deletion: CDP maintains backed up data of the VMs at the staging location in proprietary format files. If these files for a VM are accidentally deleted or corrupted, the subsequent backup job for the VM fails, citing data integrity mismatch. In this case, you can initiate a force rescan schedule backup, and subsequently, a full sync of the VM takes place.
Following a manually triggered force-rescan schedule.
CDP service can initiate full sync to receive VM data whenever necessary.
During full sync, data flows from the ESXi to the CDP gateway. Depending on the data size of the VMs, the volume of this data can be substantially large that can consume plenty of resources like network, memory, processing power, and storage. This also affects the backup operations of the VMs subscribed earlier.
If you subscribe more than 5 VMs at a time, say 7, then, full sync is initiated for 5 VMs, and 2 are in wait state.
Therefore, it is recommended to limit the number of concurrent full sync operations to optimize system resources. The default number of concurrent full sync is 5. This allows 5 VMs to perform full sync concurrently. Other VMs needing full sync need to wait in a queue. This way, the system resources are managed optimally.
Recommendation for controlling full sync:
Subscribe the VMs in batches of five or less.
Once a subscribed VM completes full sync, you can see a message in the UI, then you can proceed to subscribe the next batch.
See Defining the CDP gateway . for information on how to configure full sync on NetBackup version 10.0 onwards.
In NetBackup 9.1, you can configure the number of concurrent full sync operations by specifying a value for the CCT_MAX_FULL_SYNC_REQS parameter, in the nbcct.conf
file. For example, CCT_MAX_FULL_SYNC_REQS=7