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Browse Prior Art Database

Autonomic recovery of Peer to Peer Extend Distance (PPRC-XD) Relationship

IP.com Disclosure Number: IPCOM000097465D
Original Publication Date: 2005-Mar-07
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 22K

Publishing Venue

IBM

Abstract

A method for autonomically resynchronizing a suspended PPRC-XD pair.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 51% of the total text.

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Autonomic recovery of Peer to Peer Extend Distance (PPRC-XD) Relationship

Disclosed is a method for autonomically resynchronizing a Peer-to-Peer Extended Distance (PPRC-XD) pair that had previously been suspended.

When the primary volume in a PPRC-XD relationship is unable to continue sending updates of data to the corresponding secondary volume due to problems with the primary volume, the secondary volume or the communication path between the two, the pair goes into a suspended state. In a suspended state, the primary volume records the changes made to the data, but does not attempt to transmit those changes to the secondary volume. After the suspension, the copy of the data on the secondary volume becomes increasingly down-level since the primary volume continues to be updated, but not the secondary volume.

Many errors that cause a suspension are of a temporary nature but without this invention, a manual administrative action is required to resynchronize the pairs and cause the primary volume to resume transmitting data to the secondary volume. There may be a significant time delay between the time of the suspension event and when a qualified person is contacted and able to initiate a resynchronization.

This invention describes a method of recognizing when a suspension occurs and autonomically initiating a resynchronization for those cases where it is appropriate to do so. The process of automatically attempting to resynchronize a suspended pair is referred to as an "auto- unsuspend."

Suspensions of a PPRC-XD pair can occur for many different reasons. Each of these reasons is categorized as being either eligible or non-eligible for auto-unsuspend. Examples suspension reasons that are eligible for auto-unsuspend are a temporar...