1. A method comprising: a first node detecting that no failover nodes are available, wherein the first node comprises a local cache and a first local cache identifier, the first node is coupled to a shared storage device, and the shared storage device comprises a global cache identifier; determining whether to allow write-back caching on the first node, wherein the determining is performed in response to the detecting; and if write-back caching is allowed on the first node, incrementing the first local cache identifier and the global cache identifier.