Skip to main content
Sign Out

Welcome to Dell

My Account
  • Place orders quickly and easily
  • View orders and track your shipping status
  • Enjoy members-only rewards and discounts
  • Create and access a list of your products
  • Manage your Dell EMC sites, products, and product-level contacts using Company Administration.
Sign In Create an Account Dell Financial Services Premier Sign In Partner Program Sign In
Contact Us

Your Dell.com Carts

Dell SRDF Introduction

PDF

SRDF/Metro resilience

In normal operation, PowerMaxOS and HYPERMAX OS use the SRDF links to maintain consistency of the data on both sides of a SRDF/Metro pair. That consistency of data cannot be ensured when hosts have write access to both sides and either of the following occurs:

  • The device pair becomes Not Ready (NR) on the SRDF link.
  • One of the devices in the pair fails.

In either situation, SRDF/Metro selects one device in the pair to remain accessible to the host (the winner) and make the other device inaccessible (the loser). This decision applies to all device pairs in the SRDF/Metro configuration.

SRDF/Metro provides two ways of selecting the winner and loser:

  • Witness
  • Device bias

The following sections explain these methods and provide background information about how SRDF/Metro ensures that no data is lost due to the failure.

NOTE:The selected method comes into effect only when a failure occurs and the devices pairs are ActiveActive or ActiveBias. Before transitioning to one of those states, only one side of a pair is accessible to the host. So there is no need for SRDF/Metro to take any special action.

Rate this content

Accurate
Useful
Easy to understand
Was this article helpful?
0/3000 characters
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please select whether the article was helpful or not.
  Comments cannot contain these special characters: <>()\