Increase (virtual) DS8000 capacity limits

(virtual) DS8000 capacity is limited to 3652 TiB (approx. 4 PB) with thin provisioning and Small Extents (Thin provisioning and Small Extents is recommended by IBM)

2019 (with) DS8880 we were hit by this limitation. We used some overprovisioning (flexible mix of 3390-Model54, EAVs V1 (220 GB) and EAV V2 (1 TB)) and multiple Volume Sets for for FlashCopy (Volume FlashCopy with NOCOPY).

At Share.org I talked with Beth Peterson and asked for “break the 4PB barrier with the actual Hardware Generation (Microcode) or the next generation of hardware”. Beth told me the limitations also exist at new DS8900F, but Beth understands our problem.

With some DS8900F Systems we’ve provisioned approx. 1.7 PB Base-Volumes (as FlashCopy Source) and approx. 1.7 PB Base-Volumes (as FlashCopy Target). Consistent FlashCopy with CSM/FCMGR works fine.

With FlashCopy we need the same (virtual) capacity for FlashCopy Source and FlashCopy Target.

Cyber Resilience: Together with IBM we like to improve this LCP (Logical Corruption Protection) to SGC (SafeGuarded Copy).

With SGC IBM has changed the factor of “SafeGuarded Copy Backup Capacity” (Backup capacity Multiplier) to the minimum of 1.5

IBM Documentation: The minimum Backup capacity multiplier number is 1.5

FlashCopy (all Volumes) works fine (with our actual configuration).

SGC is not able to do LCP protection (with our actual configuration).

The actual limitations of DS8900F and implementation of SGC are growth inhibiters.

Requirement

• Increase the (virtual) DS8000 capacity limit (flexible, configurable and not hardcoded)

and/or

• decrease the Backup capacity multiplier number

and/or

• manage “SafeGuarded Copy Backup Capacity” outside the (virtual) DS8000 capacity limit