SAN Volume Controller: Best Practices and Performance Guidelines

Chapter 6.5.3. Persistent reserve

Page 89

Chapter 6. MDisks 89 6.5.1 Adding MDisks for capacity Before adding MDisks to existing MDGs, ask yourself first why you are doing this? If MDisks are being added to the SVC cluster to provide additional capacity, consider adding them to a new MDG. Recognize that adding new MDisks to existing MDGs will reduce the reliability characteristics of the MDG and risk destabilizing the MDG if hardware problems exist with the new LUNs. If the MDG is already meeting its performance objectives, we recommend that, in most cases, you add the new MDisks to new MDGs rather than add the new MDisks to existing MDGs. 6.5.2 Checking access to new MDisks You must be careful when adding MDisks to existing MDGs to ensure the ...