Configure DRS
DRS enables the system to perform real-time monitoring on compute and storage resources of a cluster and dynamically allocate resources to VMs.
If the available resources of a host are insufficient for its VMs, the system automatically migrates the VMs to other hosts to ensure that each VM can obtain sufficient resources. After you enable DRS, you do not need to monitor the CPU usage and memory usage of the VMs in the cluster, even if the VMs run the SQL server services. Automatic resource allocation and load balancing also reduce the data center cost greatly.
DRS includes compute DRS and storage DRS.
Compute DRS performs regular monitoring on the CPU usage and memory usage of hosts in the cluster through the heartbeat mechanism. If the resource usage of a host exceeds the set threshold, the system automatically migrates VMs on the host to other hosts in the cluster until the resource usage of the host falls below the threshold.
Storage DRS monitors the disk I/O throughput, IOPS, or disk usage of shared storage pools on a host and migrates VM image files between the shared storage pools to balance the storage loads.
DRS is applicable to scenarios where service load surges occur frequently.
DRS provides the following benefits:
Consolidates servers to reduce the IT cost and enhances the service flexibility.
Reduces the downtime and ensures the service continuity and stability.
Requires fewer servers and the improves the resource usage.
Procedure
On the top navigation bar, click Hosts, and then select Cluster Management > Cluster Configuration from the navigation pane.
Click DRS.
Configure the DRS parameters as described in "Parameters."
Click Save.
Parameters
Enable Compute DRS: Set the state of compute DRS.
Duration: Specify the time to wait for DRS to take effect after the CPU usage, memory usage, or traffic reaches or exceeds the set threshold. For example, if you set the value of this parameter to 10, DRS takes effect ten minutes after the CPU usage, memory usage, or traffic reaches or exceeds the specified threshold.
Interval: Specify the interval at which the system checks the host state.
Measurement: Select the resources to monitor. Options include CPUs, Memory, and Traffic.
Relation: Select the relation between the thresholds. You must configure this parameter if you select multiple options for the Measurement parameter.
CPU: Set the CPU usage threshold.
Memory: Set the memory usage threshold.
Traffic: Set the traffic threshold.
Enable Storage DRS: Set the state of storage DRS. Storage DRS takes effect on a host only when the host is mounted with all shared storages of the cluster.
Duration: Specify the time to wait for DRS to take effect after the storage usage, disk I/O, or number of disk requests reaches or exceeds the set threshold. For example, if you set the value of this parameter to 10, DRS takes effect ten minutes after the storage usage, disk I/O, or number of disk requests reaches or exceeds the specified threshold.
Interval: Specify the interval at which the system checks the host state.
Measurement: Select the resources to monitor. Options include Storage Usage, Disk I/O, and Disk Req..
Storage Usage: Set the storage usage threshold.
Disk I/O: Set the disk I/O threshold.