Device DAX (
devdax) provides a means for applications to directly access storage, without the involvement of a file system. The benefit of device DAX is that it provides a guaranteed fault granularity, which can be configured using the
--align option with the
ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax --align=2M
The given command ensures that the operating system would fault in 2MiB pages at a time. For the Intel 64 and AMD64 architecture, the following fault granularities are supported:
Device DAX nodes (
/dev/daxN.M) only supports the following system call:
write() variants are not supported because the use case is tied to persistent memory programming.