Today I was going through Vmware Resource Management Guide and found the below information and thought of sharing it across. The below information points to the faults which can occur in an environment and the reason why this fault has happened.
Having knowledge of common faults that can occur in an environment can help us to understand the issue and starting the troubleshooting.
Virtual Machine is Pinned
This fault occurs when DRS cannot move a virtual machine because DRS is disabled on it. That is, the virtual machine is “pinned” on its registered host.
Virtual Machine not Compatible with any Host
This fault occurs when DRS cannot find a host that can run the virtual machine.
This might occur, for example, if no host can satisfy the virtual machine’s CPU or memory resource needs or if no host currently has network or storage access needed by the virtual machine.
VM/VM DRS Rule Violated when Moving to another Host
This fault occurs when more than one virtual machines running on the same host and share affinity rules with each other cannot be moved to another host.
This might occur because not all the virtual machines can vMotion off the current host. For example, one of the virtual machines in the group is DRS-disabled.
Host Incompatible with Virtual Machine
This fault occurs when DRS considers migrating a virtual machine to a host, but finds that the host is incompatible with the given virtual machine.
This might occur because the target host does not have access to the network or storage connection needed by the virtual machine. Another reason this fault occurs is if the target host has a CPU that differs sufficiently from the current host so that using vMotion amongst the hosts is not supported.
To avoid this, create clusters such that all hosts are configured consistently and vMotion is compatible amongst the hosts.
Another reason the host is incompatible with the virtual machine is that there is a required VM/Host DRS rule in place that instructs DRS to never place this virtual machine on this host.
Host has Virtual Machine that Violates VM/VM DRS Rules
This fault occurs when the virtual machine, when powered on or moved by starting vMotion, would violate a VM/VM DRS rule.
The virtual machine can still be manually powered on or moved with vMotion, but vCenter Server cannot automatically do so.
Host has Insufficient Capacity for Virtual Machine
This fault occurs when the host does not have enough CPU or memory capacity for running the virtual machine.
Host in Incorrect State
This fault occurs when the host is entering maintenance or standby state when needed for DRS action to occur.
To address this fault, cancel the request for the host to enter standby or maintenance mode.
Host has Insufficient Number of Physical CPUs for Virtual Machine
This fault occurs when the host hardware does not enough physical CPUs (hyperthreads) to support the number of virtual CPUs in the virtual machine.
Host has Insufficient Capacity for Each Virtual Machine CPU
This fault occurs when the host does not have enough CPU capacity for running the virtual machine.
The Virtual Machine is in vMotion
This fault occurs when DRS cannot move a virtual machine because it is already in vMotion state.
No Active Host in Cluster
This fault occurs when the cluster in which the virtual machine is being moved does not contain any hosts that are connected and in a non-maintenance state.
This can occur, for example, if all the hosts are disconnected or in maintenance mode.
This fault occurs when an attempted operation conflicts with a resource configuration policy.
This fault may occur, for example, if a power-on operation reserves more memory than is allocated to a resource pool.
Retry the operation after adjusting the resources to allow more memory.
Insufficient Resources to Satisfy Configured Failover Level for HA
This fault occurs when the HA configuration of CPU or memory resources reserved for failover is violated or cannot be met by the DRS operation under consideration.
This fault is reported when:
- The host is requested to enter maintenance or standby mode.
- The Virtual machine violates failover when it attempts to power on.
No Compatible Hard Affinity Host
No host is available for the virtual machine that satisfies its mandatory VM/Host DRS affinity or anti-affinity rules.
No Compatible Soft Affinity Host
No host is available for the virtual machine that satisfied its preferred VM/Host DRS affinity or anti-affinity rules.
Soft Rule Violation Correction Disallowed
DRS migration threshold is set at mandatory-only.
This does not allow the generation of DRS actions to correct non-mandatory VM/Host DRS affinity rules.