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For example, see namespace_rw_infoblock(): https://github.com/pmem/ndctl/blob/main/ndctl/namespace.c#L2022 That facility uses the force_raw attribute ("/sys/bus/nd/devices/namespaceX.Y/force_raw") to arrange for the namespace to initalize without considering any pre-existing metdata *and* without overwriting it. In that mode makedumpfile can walk the namespaces and retrieve the metadata written by the previous kernel. The module to block to allow makedumpfile to access the namespace in raw mode is the nd_pmem module, or if it is builtin the nd_pmem_driver_init() initcall.