Documentation for ndctl and daxctl


ndctl-wait-scrub - wait for an Address Range Scrub (ARS) operation to complete


ndctl wait-scrub [<bus-id> <bus-id2> …​ <bus-idN>] [<options>]


NVDIMM Address Range Scrub is a capability provided by platform firmware that allows for the discovery of memory errors by system software. It enables system software to pre-emptively avoid accesses that could lead to uncorrectable memory error handling events, and it otherwise allows memory errors to be enumerated.

The kernel provides a POLL(2) capable sysfs file (scrub) to indicate the state of ARS. The scrub file maintains a running count of ARS runs that have taken place. While a current run is in progress a + character is emitted along with the current count. The ndctl wait-scrub operation waits for scrub, across all specified buses, to indicate not in-progress at least once.


Wait for scrub on all nvdimm buses in the system. The json listing report at the end only includes the buses that support ARS operations.

# ndctl wait-scrub

When specifying an individual bus, or if there is only one bus in the system, the command reports whether ARS support is available.

# ndctl wait-scrub e820
error waiting for scrub completion: Operation not supported


-v; --verbose
Emit debug messages for the ARS wait process


Copyright © 2016 - 2020, Intel Corporation. License GPLv2: GNU GPL version 2 This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.


ndctl-start-scrub , ACPI 6.2 Specification Section Address Range Scrubbing (ARS) Overview