Dell Unity™ Family VNX® Series Data Import to Unity All Flash or Hybrid, or UnityVSA™ System User Guide

Block import

Unisphere allows you to import multiple concurrent block import sessions for either LUNs or Consistency Group (CG) of LUNs, from the VNX system to the Unity system. This limit is based on the SAN Copy limits of the source VNX system and is also based on the number of members in each CG. Block import uses the SAN Copy feature on the VNX storage system to push data to the Unity storage system. Use the VNX management IP address and VNX Admin credentials to configure a remote system connection from the target Unity system to the source VNX system. The VNX SAN Copy FC or iSCSI initiators are discovered through this connection and the Unity system is registered as a SANCopy host. Also, all block resources that are eligible for import are discovered, which includes:

• Pool LUNs, Thin LUNs, and Meta LUNs that are:
  • Not reserved LUN pool LUNs
  • Not LUNs exposed to VNX file
  • Not System LUNs
• CGs of LUNs

Before you perform an import of a LUN or CG of LUNs, the reserved LUN pool (RLP) on the source VNX system should contain at least one free LUN for each LUN planned for import. Each reserved LUN can vary in size. However, using the same size for each LUN in the pool is easier to manage because the LUNs are assigned without regard to size. That is, the first available free LUN in the global reserved LUN pool is assigned. Since you cannot control which reserved LUNs are being used for a particular import session or a VNX process such as SnapView™, incremental SAN Copy, or MirrorView/A, use a standard size for all reserved LUNs. To assist in estimating a suitable reserved LUN pool size for the storage system, consider the following:

• If you want to optimize space utilization, use the size of the smallest source LUN as the basis of the calculations. If you want to optimize the total number of source LUNs, use the size of the largest source LUN as the basis of the calculations.
• If you have a standard online transaction processing configuration (OLTP), use reserved LUNs sized at 10-20%. This size tends to be appropriate to accommodate the copy-on-first-write activity.
• If you are also using SnapView or MirrorView/A on the VNX LUN, then you may need additional RLP LUNs.

For more information about the RLP and reserved LUNs, refer to the Unisphere online help on the source VNX.