NDCTL-WAIT-SCRUB(1) ndctl Manual NDCTL-WAIT-SCRUB(1)

# [NAME](#NAME)

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

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#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)](/man/os/ndctl/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](#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":"idle"


  },


  {


    "provider":"nfit_test.0",


    "dev":"ndbus2",


    "scrub_state":"idle"


  }
]
```

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
```

# [OPTIONS](#OPTIONS)

-v, --verbose

Emit debug messages for the ARS wait process

# [COPYRIGHT](#COPYRIGHT)

Copyright © 2016 - 2022, Intel Corporation. License GPLv2: GNU GPL version 2 &lt;http://gnu.org/licenses/gpl.html&gt;. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

# [SEE ALSO](#SEE_ALSO)

[ndctl-start-scrub(1)](/man/os/ndctl/ndctl-start-scrub.1), *ACPI* &lt;http://www.uefi.org/sites/default/files/resources/ACPI%206\_2\_A\_Sept29.pdf&gt; 6.2 Specification Section 9.20.7.2 Address Range Scrubbing (ARS) Overview"

2026-08-31 ndctl

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Document: ndctl-wait-scrub(1) from ndctl 85-r2 (Chainguard OS)
Source: https://github.com/pmem/ndctl