'\" t
.\" Title: nvme-compare
.\" Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
.\" Generator: DocBook XSL Stylesheets vsnapshot
.\" Date: 02/19/2024
.\" Manual: NVMe Manual
.\" Source: NVMe
.\" Language: English
.\"
.TH "NVME\-COMPARE" "1" "02/19/2024" "NVMe" "NVMe Manual"
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.SH "NAME"
nvme-compare \- Send an NVMe Compare command, provide results
.SH "SYNOPSIS"
.sp
.nf
\fInvme\-compare\fR [\-\-start\-block= | \-s ]
[\-\-block\-count= | \-c ]
[\-\-data\-size= | \-z ]
[\-\-metadata\-size= | \-y ]
[\-\-ref\-tag= | \-r ]
[\-\-data= | \-d ]
[\-\-metadata= | \-M ]
[\-\-prinfo= | \-p ]
[\-\-app\-tag\-mask= | \-m ]
[\-\-app\-tag= | \-a ]
[\-\-limited\-retry | \-l]
[\-\-force\-unit\-access | \-f]
[\-\-dir\-type= | \-T ]
[\-\-dir\-spec= | \-S ]
[\-\-dsm= | \-D ]
[\-\-show\-command | \-V]
[\-\-dry\-run | \-w]
[\-\-latency | \-t]
[\-\-storage\-tag | \-g ]
[\-\-storage\-tag\-check | \-C]
[\-\-force]
[\-\-output\-format= | \-o ] [\-\-verbose | \-v]
.fi
.SH "DESCRIPTION"
.sp
The Compare command reads the logical blocks specified by the command from the medium and compares the data read to a comparison data buffer transferred as part of the command\&. If the data read from the controller and the comparison data buffer are equivalent with no miscompares, then the command completes successfully\&. If there is any miscompare, the command completes with an error of Compare Failure\&. If metadata is provided, then a comparison is also performed for the metadata\&.
.SH "OPTIONS"
.PP
\-s , \-\-start\-block=
.RS 4
64\-bit address of the first block to access\&.
.RE
.PP
\-c , \-\-block\-count=
.RS 4
Number of blocks to be accessed (zero\-based)\&.
.RE
.PP
\-z , \-\-data\-size=
.RS 4
Size of data to be compared in bytes\&.
.RE
.PP
\-y , \-\-metadata\-size=
.RS 4
Size of metadata to be transferred in bytes\&.
.RE
.PP
\-r , \-\-ref\-tag=
.RS 4
Reference Tag for Protection Information
.RE
.PP
\-d , \-\-data=
.RS 4
Data file\&.
.RE
.PP
\-M , \-\-metadata=
.RS 4
Metadata file\&.
.RE
.PP
\-p , \-\-prinfo=
.RS 4
Protection Information and check field\&.
.TS
allbox tab(:);
lt lt
lt lt
lt lt
lt lt
lt lt
lt lt.
T{
Bit
T}:T{
Description
T}
T{
3
T}:T{
PRACT: Protection Information Action\&. When set to 1, PI is stripped/inserted on read/write when the block format\(cqs metadata size is 8\&. When set to 0, metadata is passes\&.
T}
T{
2:0
T}:T{
PRCHK: Protection Information Check:
T}
T{
2
T}:T{
Set to 1 enables checking the guard tag
T}
T{
1
T}:T{
Set to 1 enables checking the application tag
T}
T{
0
T}:T{
Set to 1 enables checking the reference tag
T}
.TE
.sp 1
.RE
.PP
\-m , \-\-app\-tag\-mask=
.RS 4
App Tag Mask for Protection Information
.RE
.PP
\-a , \-\-app\-tag=
.RS 4
App Tag for Protection Information
.RE
.PP
\-l, \-\-limited\-retry
.RS 4
Number of limited attempts to media\&.
.RE
.PP
\-f, \-\-force\-unit\-access
.RS 4
FUA option to guarantee that data is stored to media\&.
.RE
.PP
\-T , \-\-dir\-type=
.RS 4
Optional directive type\&. The nvme\-cli only enforces the value be in the defined range for the directive type, though the NVMe specification (1\&.3a) defines only one directive, 01h, for write stream identifiers\&.
.RE
.PP
\-S , \-\-dir\-spec=
.RS 4
Optional field for directive specifics\&. When used with write streams, this value is defined to be the write stream identifier\&. The nvme\-cli will not validate the stream requested is within the controller\(cqs capabilities\&.
.RE
.PP
\-D , \-\-dsm=
.RS 4
The optional data set management attributes for this command\&. The argument for this is the least significant 8 bits of the DSM field in a write command; the most significant 16 bits of the field come from the directive specific field, if used\&. This may be used to set attributes for the LBAs being written, like access frequency, type, latency, among other things, as well as yet to be defined types\&. Please consult the NVMe specification for detailed breakdown of how to use this field\&.
.RE
.PP
\-V, \-\-show\-cmd
.RS 4
Print out the command to be sent\&.
.RE
.PP
\-w, \-\-dry\-run
.RS 4
Do not actually send the command\&. If want to use \-\-dry\-run option, \-\-show\-cmd option
\fImust\fR
be set\&. Otherwise \-\-dry\-run option will be
\fIignored\fR\&.
.RE
.PP
\-t, \-\-latency
.RS 4
Print out the latency the IOCTL took (in us)\&.
.RE
.PP
\-g , \-\-storage\-tag=
.RS 4
Variable Sized Expected Logical Block Storage Tag(ELBST)\&.
.RE
.PP
\-C, \-\-storage\-tag\-check
.RS 4
This flag enables Storage Tag field checking as part of end\-to\-end data protection processing\&.
.RE
.PP
\-\-force
.RS 4
Ignore namespace is currently busy and performed the operation even though\&.
.RE
.PP
\-o , \-\-output\-format=
.RS 4
Set the reporting format to
\fInormal\fR,
\fIjson\fR
or
\fIbinary\fR\&. Only one output format can be used at a time\&.
.RE
.PP
\-v, \-\-verbose
.RS 4
Increase the information detail in the output\&.
.RE
.SH "EXAMPLES"
.sp
No examples yet\&.
.SH "NVME"
.sp
Part of the nvme\-user suite