The fault zone of a process is that subset of program state which could be corrupted by the process continuing to execute after incurring a fault, for instance due to an unreliable component used in the computer executing the program.)
Other low-latency methods that allow byte-grain[clarification needed] access to data also qualify.
In this respect, persistent memory resembles more abstract forms of computer storage, such as file systems.
In fact, almost all existing persistent memory technologies implement at least a basic file system that can be used for associating names or identifiers with stored extents, and at a minimum provide file system methods that can be used for naming and allocating such extents.
If a power failure happens right after the write is made visible but not yet persistent, the read-of-non-persistent-write problem can occur, i.e., a data variable that is modified by a compare-and-swap operation can be made visible to a concurrent observer before a crash observer, causing potential crash inconsistencies.