Setting global limits on the use of Red Hat Virtualization resources
You can control the number of simultaneous backups that can be performed on an Red Hat Virtualization resource type. The settings apply to all NetBackup policies for the currently selected primary server.
For example, to avoid overloading the overall Red Hat Virtualization cluster, you can place a limit on the number of concurrent backup jobs per Red Hat Virtualization Cluster. To control input output overhead on the storage domain array, you can limit the number of concurrent backups per storage domain.
The following resource limits are available for Red Hat Virtualization:
Backup Jobs per Cluster
Backup Jobs per DataCenter
Backup Jobs per StorageDomain
To set limits on the use of Red Hat Virtualization resources
- On the left, click Workloads > Red Hat Virtualization.
- On the top right, click RHV settings > Resource limits.
For each resource type, the default is 0, (No Limit).
- Select the resource type you want to change and then click Edit.
- Choose from the following options.
Set a global limit for a RHV resource type.
Locate the Global setting and select the Limits value that you want to apply.
This value limits the number of simultaneous backups that are performed for the resource type.
Set a limit for a specific RHV resource.
Click Add.
Provide a name for the resource limit.
Select the Limits value that you want to apply.
This value limits the number of simultaneous backups that are performed for the specific resource.
The following example illustrates how these limits control simultaneous backups. The settings must be done according to Red Hat Virtualization configuration in your environment.
When NetBackup connects to the Red Hat Virtualization environment for backup, it makes 1 connection per disk present on the VM. So, if a VM has 2 disks then NetBackup would make 2 connections with the Red Hat Virtualization node.
So, consider a case where Red Hat Virtualization manager is managing 2 clusters with 2 nodes in each cluster. Let's consider every node is hosting 20 VMs with 2 disks on each VM.
When the job runs, there would be 80 concurrent jobs start if no Resource Limit is set which is default behavior. Red Hat Virtualization recommends up to 10 disk connections concurrently per node in the cluster. In the example of each VM with two disks, 5 VMs per node can be ideally backed up concurrently. Hence, in this case of a cluster with two nodes, it is recommended to backup upto 10 VMs concurrently. When the Backup Jobs per Cluster is set to 10, this limit is enforced.
Since one data center can manage multiple clusters, Backup Jobs per DataCenter resource limit could be higher than Backup Jobs per Cluster. You need to determine the values by evaluating the effect of backup on overall environment.
Storage domain in Red Hat Virtualization can server multiple clusters in a data center. It serves to protection VM as well as backup. Its performance is dependent on type of storage technology - FC, iSCSI, NFS, gluster etc. Hence limit on storage domain using Backup Jobs per StorageDomain can be set based on characteristics of storage domain technology and limit can be higher than Backup Jobs per Cluster.