Browse Prior Art Database

Multiple bi-directional process logins over a single fibre channel PPRC link

IP.com Disclosure Number: IPCOM000032687D
Original Publication Date: 2004-Nov-10
Included in the Prior Art Database: 2004-Nov-10
Document File: 3 page(s) / 31K

Publishing Venue

IBM

Abstract

This invention allows a PPRC port to manage multiple instances of bi-directional logins.

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

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Multiple bi-directional process logins over a single fibre channel PPRC link

In a fibre channel PPRC environment, there may exist data centers A and B that need to backup their data to remote data center C. Data center C also has the need to backup its data. With bi-directional PPRC it is possible for data center C to be both primary and secondary to data center A, and also be both primary and secondary to data center B. This allows both data centers A and B to store copies of their data at data center C, and also for data center C to store copies of its data at both data centers A and B. With bi-directional PPRC, data center C would be required to use separate fibre channel links for each bi-directional PPRC path.

Not sharing a single link at data center C has drawbacks. One obvious downside is the added cost to acquire and maintain separate physical links. This is especially true when the link is over a long distance. Other drawbacks are that data center C has the additional resource overhead of maintaining two fibre channel adapters, and data center C has less adapter resources available.

With this invention, a single fibre channel link can be used for multiple instances of PPRC in both directions. At one end of the link, data center C can use a single adapter concurrently as both PPRC primary and PPRC secondary to separate adapters at data centers A and B on the other ends of the link. This allows for less cost and maintenance at data center C than would be required for two separate lines. It also allows data center C to use its adapter resources for other purposes.

This invention provides a means to concurrently use multiple instances of bi-directional PPRC on a single fibre channel port, except that the port now has the ability to manage multiple instances of bi-directional logins.

In present PPRC implementations, two remote data centers that are both primary and secondary to eachother do not share a single fibre channel link to back up data in both directions. Current methods to back up data in both directions over fibre channel require two dedicated lines between the two remote data centers. One line is used for data traveling in each direction.

Not sharing a single line has several drawbacks. The obvious downside is the added cost of acquiring and maintaining two separate physical links. This is especially true when the link is over a long distance. Another downside is not taking advantage of the full duplex capabilities of fibre channel. It is possible to utilize twice the bandwidth of the link if data is being sent in both directions. This way a 2G fibre channel link will give 2G of bandwidth to each PPRC pair, and a total of 4G of bandwidth will be utilized by a single link.

A solution is required that will utilize a single link for the data transfer in both directions.

This invention allows a single fibre channel link to be used for PPRC in both directions. At each end of the link, the same adapter is concurrently bot...