ndctl-start-scrub - Man Page

start an Address Range Scrub (ARS) operation

Synopsis

ndctl start-scrub [<bus-id> <bus-id2> ... <bus-idN>] [<options>]

Description

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 sysfs file (scrub) that when written with the string "1\n" initiates an ARS operation. The ndctl start-scrub operation starts an ARS, across all specified buses, and the kernel in turn proceeds to scrub every persistent memory address region on the specified buses.

Example

Start a scrub on all nvdimm buses in the system. The json listing report only includes the buses that support ARS operations.

.ft C
# ndctl start-scrub
[
  {
    "provider":"nfit_test.1",
    "dev":"ndbus3",
    "scrub_state":"active"
  },
  {
    "provider":"nfit_test.0",
    "dev":"ndbus2",
    "scrub_state":"active"
  }
]
.ft

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

.ft C
# ndctl start-scrub e820
error starting scrub: Operation not supported
.ft

Options

-v, ā€‰--verbose

Emit debug messages for the ARS start process

See Also

ndctl-wait-scrub(1), ACPI 6.2 Specification Section 9.20.7.2 Address Range Scrubbing (ARS) Overview[1]

Notes

1.

ACPI 6.2 Specification Section 9.20.7.2 Address Range Scrubbing (ARS) Overview
http://www.uefi.org/sites/default/files/resources/ACPI%206_2_A_Sept29.pdf

Referenced By

ndctl-clear-errors(1), ndctl-wait-scrub(1).

01/26/2021 ndctl 71.1 ndctl Manual