'\" t
.\"     Title: nvme-feat-perfc
.\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 09/07/2026
.\"    Manual: NVMe Manual
.\"    Source: NVMe
.\"  Language: English
.\"
.TH "NVME\-FEAT\-PERFC" "1" "09/07/2026" "NVMe" "NVMe Manual"
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.SH "NAME"
nvme-feat-perfc \- Get and set performance characteristics feature
.SH "SYNOPSIS"
.sp
.nf
\fInvme\fR [<global\-options>] \fIfeat perfc\fR <device>
                        [\-\-namespace\-id=<nsid> | \-n <nsid>] [\-\-attri=<attri> | \-a <attri>]
                        [\-\-rvspa | \-r] [\-\-r4karl=<r4karl> | \-R <r4karl>]
                        [\-\-paid=<paid> | \-p <paid>] [\-\-attrl=<attrl> | \-A <attrl>]
                        [\-\-vs\-data=<file> | \-V <file>]
                        [\-\-sel=<select> | \-S <select>] [\-\-save | \-s]
.fi
.SH "DESCRIPTION"
.sp
Get and set performance characteristics feature\&.
.sp
The <device> parameter is mandatory and may be either the NVMe character device (ex: /dev/nvme0), or a namespace block device (ex: /dev/nvme0n1)\&.
.sp
If any of the setting options (\-\-rvspa, \-\-r4karl, or \-\-paid) are specified, the command will update the performance characteristics configuration\&. If none of these options are specified, it will retrieve and display the current configuration\&.
.sp
On success it returns 0, error code otherwise\&.
.SH "OPTIONS"
.PP
\-n <nsid>, \-\-namespace\-id=<nsid>
.RS 4
Optional namespace attached to controller\&.
.RE
.PP
\-a <attri>, \-\-attri=<attri>
.RS 4
Attribute index\&. Specifies the performance attribute index to set or get\&.
.RE
.PP
\-r, \-\-rvspa
.RS 4
Revert vendor specific performance attribute flag\&.
.RE
.PP
\-R <r4karl>, \-\-r4karl=<r4karl>
.RS 4
Random 4 KiB average read latency\&.
.RE
.PP
\-p <paid>, \-\-paid=<paid>
.RS 4
Performance attribute identifier\&. Must be a valid UUID string format\&.
.RE
.PP
\-A <attrl>, \-\-attrl=<attrl>
.RS 4
Attribute length\&. Required when using vendor specific performance data\&.
.RE
.PP
\-V <file>, \-\-vs\-data=<file>
.RS 4
Vendor specific data input file path\&. Reads data buffer from the specified file\&.
.RE
.PP
\-S <select>, \-\-sel=<select>
.RS 4
Select (SEL): This field specifies which value of the attributes to return in the provided data:
.RE
.PP
\-s, \-\-save
.RS 4
Save the attribute so that it persists through all power states and resets\&.
.RE
.SH "GLOBAL OPTIONS"
.sp
The following options are defined at the top\-level nvme command and are available to this subcommand:
.PP
\-\-dry\-run
.RS 4
Print the command that would be executed, but do not actually execute it\&.
.RE
.PP
\-\-no\-ioctl\-probing
.RS 4
Disable probing for 64\-bit IOCTL support\&.
.RE
.PP
\-\-no\-retries
.RS 4
Disable retry logic on transient errors\&.
.RE
.PP
\-o <fmt>, \-\-output\-format=<fmt>
.RS 4
Set the reporting format to
\fInormal\fR,
\fItabular, \*(Aqjson\fR, or
\fIbinary\fR\&. Only one output format may be used at a time\&.
.RE
.PP
\-\-output\-format\-version=<version>
.RS 4
Select the output format version\&. Version
\fI1\fR
uses the original field naming, while version
\fI2\fR
(default) provides more consistent and script\-friendly field names\&.
.RE
.PP
\-\-timeout=<ms>
.RS 4
Set the timeout for the command in milliseconds\&.
.RE
.PP
\-v, \-\-verbose
.RS 4
Increase the level of detail in the output\&. May be specified multiple times to further increase verbosity\&.
.RE
.sp
These options can also be set as machine\-wide defaults in nvme\-cli\&.conf(5)\&. A command\-line flag always overrides the file\&.
.SH "EXAMPLES"
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Has the program issue a feat perfc to get the current configuration:
.sp
.if n \{\
.RS 4
.\}
.nf
# nvme feat perfc /dev/nvme0
.fi
.if n \{\
.RE
.\}
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Has the program issue a feat perfc to set standard performance attributes:
.sp
.if n \{\
.RS 4
.\}
.nf
# nvme feat perfc /dev/nvme0 \-\-attri=0 \-\-r4karl=10 \-\-save
.fi
.if n \{\
.RE
.\}
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Has the program issue a feat perfc to set vendor specific data from a file:
.sp
.if n \{\
.RS 4
.\}
.nf
# nvme feat perfc /dev/nvme0 \-\-attri=128 \-\-paid=12345678\-1234\-1234\-1234\-123456789abc \-\-attrl=64 \-\-vs\-data=vs_buf\&.bin
.fi
.if n \{\
.RE
.\}
.RE
.SH "NVME"
.sp
Part of the nvme\-user suite\&.