SAN Volume Controller: Best Practices and Performance Guidelines

Chapter 11.7. Failure boundaries

Page 214

214 SAN Volume Controller: Best Practices and Performance Guidelines 11.7 Failure boundaries There is one more thing to consider, and that is failure boundaries. If all of the LUNs are spread across all physical disks ( and all RAID arrays, in other words, you are using striped VDisks), and if you lose a single RAID array, you lose all your data. So there are situations in which you probably want to limit the spread for certain applications or groups of applications. You might have a group of applications where if one application fails, none of the applications can do any productive work. This is a good group of applications to share the same set of back- end disks due to the failure boundary. Alternatively, ...