Will changing the queue depth on windows VM from 64 to 256 having any impact on the queueing on NetApp NVMe namespace
Applies to
- NVMe/FC
- ESXi hypervisor with windows VMs.
Answer
- Beginning with ONTAP 9.14.1, we can configure NVMe subsystem to prioritize resource allocation for specific hosts.
- ONTAP NVMe supports hosts with 'regular' & 'high' priority, and will be available when hosts are added to subsystems.
- These options translate to different NVMe queue-counts and queue-depths based on ONTAP hardware platform and the NVMe-oF transport used by the host.
- So, if we want all the ESXi servers to have higher number of queues and higher queue depth, we would need to set the host priority to 'high' for these hosts and this can be done when adding the hostnqns to the ONTAP NVMe subsystem.
- Those hosts which have default 'regular' priority have a limited set of queues and those which are set to 'high' priority have higher number of queues & queue-depth.
- Hosts assigned a high priority are allocated larger I/O queue counts and queue-depths.
Additional Information
- By default, when a host is added to the subsystem, it is assigned a regular priority.
- The support for host priorities enable NVM subsystems to prioritize hosts differently.