ndctl−wait−scrub(1)

NAME SYNOPSIS DESCRIPTION EXAMPLE OPTIONS COPYRIGHT SEE ALSO

NAME

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

SYNOPSIS

ndctl wait−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 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.

EXAMPLE

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
[
{
"provider":"nfit_test.1",
"dev":"ndbus3",
"scrub_state":"active"
},
{
"provider":"nfit_test.0",
"dev":"ndbus2",
"scrub_state":"active"
}
]

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

# ndctl start−scrub e820
error starting scrub: Operation not supported

OPTIONS

−v, −−verbose

Emit debug messages for the ARS wait process

COPYRIGHT

Copyright (c) 2016 − 2019, Intel Corporation. License GPLv2: GNU GPL version 2 http://gnu.org/licenses/gpl.html. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

ndctl−start−scrub(1), ACPI http://www.uefi.org/sites/default/files/resources/ACPI%206_2_A_Sept29.pdf 6.2 Specification Section 9.20.7.2 Address Range Scrubbing (ARS) Overview"