When you use I/O filters in your environment, follow specific guidelines and best practices.

  • I/O filters do not support RDMs in physical compatibility mode.
  • Flash Read Cache and caching I/O filters are mutually exclusive because both functionalities use the virtual flash resource on the host. You cannot enable Flash Read Cache on a virtual disk with the cache I/O filters. Similarly, if a virtual machine has Flash Read Cache configured, it cannot use the cache I/O filters.
  • You cannot change or assign the I/O filter policy when migrating or cloning a virtual machine.
  • Cloning or migration of a virtual machine with I/O filter policy from one host to another requires the destination host to have a compatible filter installed. This requirement applies to migrations initiated by an administrator or by such functionalities as HA or DRS.
  • When you convert a template to a virtual machine, and the template is configured with I/O filter policy, the destination host must have the compatible I/O filter installed.
  • If you use vCenter Site Recovery Manager to replicate virtual disks, the resulting disks on the recovery site do not have I/O filter policies. You must create I/O filter policies in the recovery site and reattach them to the replicated disks.
  • If your virtual machine has a snapshot tree associated with it, you cannot add, change, or remove the I/O filter policy for the virtual machine.

For information about troubleshooting I/O filters, see the vSphere Troubleshooting documentation.