Friday, September 26, 2008

Learning - DS3000 Storage Family support for REMOTE MIRRORING

Storage Question:

I’m currently involved in an opportunity that requires remote replication. I heard that there is a new update to the DS3000 line, and I was wondering if Remote Mirroring was included in the expanded enhancements. If not, any other suggestions?


The short answer to the question is NO. The DS3000 series was not designed to support remote mirroring. Although it is loosely based on the same firmware as the DS4000, there are some key differences. These include:

- Limited number of host ports. The firmware on the DS4000 likes to allocate host ports for mirroring for a variety of reasons. With just two host ports/controller, the functionality of the system would be severely limited if mirroring was implemented.

- Limited Cache support. The DS3000 series can be uplifted to support 1GB of cache per controller. This is not a lot of cache if the controller is processing IO’s for hosts and acting as an initiator for remote mirroring.

- Limited host support. The limited number of partitions makes this box designed for the entry-level market. This is not usually a market that requires remote mirroring. On the occasion that remote mirroring is required, the bandwidth of controller based mirroring usually makes the solution cost prohibitive compared to host-level mirroring.

The upcoming enhancements will expand the capabilities of the DS3000 systems, but adding remote mirroring is not one of the additional features. To learn more about the new update, please attend the webcast on Oct 14th (see attached).

So, the question of which host-level mirroring would be suggested?

Well, there are a few that come to mind, so I’ll just mention the leaders of the pack. I believe all of those listed below are storage proven.

*) Tivoli Storage Manager FastBack

*) NSI DoubleTake

Please note an upcoming webcast to discuss this solution on Thursday, Oct 9th at 2:00 pm EDT (see attached doc)

*) CA XOsoft Replication

*) Symantec Veritas Volume Replicator

*) IBM Softek Replicator

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