Policy Based Replication (aka PBR) is required at version 8.7.0.1, and we would like it to be adjusted as an option vs requiring the undoing of Global Mirror Change Volumes (aka GMCV) replication.

MEDHOST is currently configured with an SVC that has 9 nodes (one being a hot spare) and 4 IO groups clustered as a single storage pool. We are currently experiencing the BEST performance and reliability using this configuration since we have been using IBM SAN Storage. We are also consistently running at very low sub millisecond response times with 80% writes and 20% reads. One of the main benefits of this configuration is allowing us to have our LPARs spanning multiple IO groups which allows the latency of writes to be non-impactful to our healthcare-based customers.  This configuration also allows us to isolate our management ports on an airgap network.  This provided two benefits, the first protection is of our storage system management port and the second eliminates the need to upgrade every time there is a GUI or web security fix.  Updating the code has been a major pain point as it has caused a number of unplanned outages and performance issues.

Over time MEDHOST has gone through many configuration iterations with help of IBM FAST Team, support, flash team, storage technical team, and Lab services.  We have not experienced the amount of performance, reliability, and security until we moved to a design that has been validated by benchmarks and actual client deployments using IBMi. 

Policy Based Replication would require us to revamp our current configuration which would result in losing our success with IBM SVC / FlashSystem storage.  Based on IBM’s current storage road map, this requires the following changes:

• One pool per I/O group
• LPAR per I/O group
• Expose management port
• Loss of volume control for balancing
• Loss of overall performance

MEDHOST would like the option to continue using our current configuration which has been proven to be critical to our business and our success.  If this option cannot be provided, it will endanger not only our business but our patient’s lives.  This will force MEDHOST to re-evaluate our storage solution and vendor in order to meet our performance and reliability needs.