Home > Storage > PowerMax and VMAX > Data Protection > Dell PowerMax and VMAX All Flash: SRDF/Metro Overview and Best Practices > Use bias resiliency option
By default, SRDF/Metro uses witness resiliency where SRDF witness groups have been configured. On systems prior to PowerMaxOS, Witness resiliency may be overridden by the user by specifying a use_bias option each time links are established. This option forces the use of a ActiveBias pair state even where an ActiveActive state with witness protection may otherwise be achieved. Performing a subsequent establish operation without the use_bias option results in witness protection where available.
Use this option during testing or when scheduled maintenance of the witness system is necessary. In the event of scheduled maintenance of the witness system, using this option prevents dial home events and escalations normally associated with an outage of SRDF/Metro in a witness configuration as depicted in the witness system failure scenario below.