Manage DRS
Dynamic resource scheduling (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 the shared storage pool and migrates the VM image files 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 running servers and improves the resource usage.
Restrictions and guidelines
DRS does not take effect on VMs that use RBDs.
Procedure
From the left navigation pane, select Resources > Host Pool Name > Cluster Name.
Click DRS.
Enable DRS (compute) or DRS (storage) as needed, specify the duration and interval, and select a monitoring policy for DRS (compute) or DRS (storage).
Click OK.
Parameters
Enable DRS (Compute): Select whether to enable dynamic compute resource scheduling. After you enable this feature, the system automatically migrates online VMs to balance the compute resource loads. Configure the following parameters if you enable this feature:
Duration: Specify the time to wait for DRS to take effect after the CPU usage, memory usage, or traffic reaches or exceeds the specified threshold. For example, if you set the value of this parameter to 5, DRS takes effect five 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.
Monitoring Policy: Select a monitoring policy to monitor the host CPU usage, memory usage, and network flow.
Effective Time Period: Specify a time range during which DRS takes effect.
If the start time is earlier than the end time, the time range takes effect on the day of configuration.
If the start time is the same as the end time, DRS takes effect all the day.
If the start time is later than the end time, DRS takes effect from the start time on the day of configuration to the end time on the following day.
Enable DRS (Storage): Select whether to enable dynamic storage resource scheduling. After you enable this feature, the system automatically migrates the VM storage to balance the storage resource loads. Storage DRS takes effect on a host only when the host is mounted with all shared storage of the cluster. Configure the following parameters if you enable this feature:
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 specified threshold. For example, if you set the value of this parameter to 5, DRS takes effect five 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.