'\" t

.\"     Title: nvme-wdc-smart-add-log

.\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]

.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>

.\"      Date: 01/08/2019

.\"    Manual: NVMe Manual

.\"    Source: NVMe

.\"  Language: English

.\"

.TH "NVME\-WDC\-SMART\-AD" "1" "01/08/2019" "NVMe" "NVMe Manual"

.\" -----------------------------------------------------------------

.\" * Define some portability stuff

.\" -----------------------------------------------------------------

.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.\" http://bugs.debian.org/507673

.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html

.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.ie \n(.g .ds Aq \(aq

.el       .ds Aq '

.\" -----------------------------------------------------------------

.\" * set default formatting

.\" -----------------------------------------------------------------

.\" disable hyphenation

.nh

.\" disable justification (adjust text to left margin only)

.ad l

.\" -----------------------------------------------------------------

.\" * MAIN CONTENT STARTS HERE *

.\" -----------------------------------------------------------------

.SH "NAME"

nvme-wdc-smart-add-log \- Send NVMe WDC smart\-add\-log Vendor Unique Command, return result

.SH "SYNOPSIS"

.sp

.nf

\fInvme wdc smart\-add\-log\fR <device> [\-\-interval=<NUM>, \-i <NUM>] [\-\-output\-format=<normal|json> \-o <normal|json>]

.fi

.SH "DESCRIPTION"

.sp

For the NVMe device given, send a Vendor Unique WDC smart\-add\-log command and provide the additional smart log\&. The \-\-interval option will return performance statistics from the specified reporting interval\&.

.sp

The <device> parameter is mandatory and may be either the NVMe character device (ex: /dev/nvme0)\&.

.sp

This will only work on WDC devices supporting this feature\&. Results for any other device are undefined\&.

.sp

On success it returns 0, error code otherwise\&.

.SH "OPTIONS"

.PP

\-i <NUM>, \-\-interval=<NUM>

.RS 4

Return the statistics from specific interval, defaults to 14

.RE

.PP

\-o <format>, \-\-output\-format=<format>

.RS 4

Set the reporting format to

\fInormal\fR, or

\fIjson\fR\&. Only one output format can be used at a time\&. Default is normal\&.

.RE

.sp

Valid Interval values and description :\-

.TS

allbox tab(:);

ltB ltB.

T{

Value

T}:T{

Description

T}

.T&

lt lt

lt lt

lt lt

lt lt

lt lt.

T{

.sp

\fB1\fR

T}:T{

.sp

Most recent five (5) minute accumulated set\&.

T}

T{

.sp

\fB2\-12\fR

T}:T{

.sp

Previous five (5) minute accumulated sets\&.

T}

T{

.sp

\fB13\fR

T}:T{

.sp

The accumulated total of sets 1 through 12 that contain the previous hour of accumulated statistics\&.

T}

T{

.sp

\fB14\fR

T}:T{

.sp

The statistical set accumulated since power\-up\&.

T}

T{

.sp

\fB15\fR

T}:T{

.sp

The statistical set accumulated during the entire lifetime of the device\&.

T}

.TE

.sp 1

.SH "CA LOG PAGE DATA OUTPUT EXPLANATION"

.TS

allbox tab(:);

ltB ltB.

T{

Field

T}:T{

Description

T}

.T&

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt.

T{

.sp

\fBPhysical NAND bytes written\&.\fR

T}:T{

.sp

The number of bytes written to NAND\&. 16 bytes \- hi/lo

T}

T{

.sp

\fBPhysical NAND bytes read\fR

T}:T{

.sp

The number of bytes read from NAND\&. 16 bytes \- hi/lo

T}

T{

.sp

\fBBad NAND Block Count\fR

T}:T{

.sp

Raw and normalized count of the number of NAND blocks that have been retired after the drives manufacturing tests (i\&.e\&. grown back blocks)\&. 2 bytes normalized, 6 bytes raw count

T}

T{

.sp

\fBUncorrectable Read Error Count\fR

T}:T{

.sp

Total count of NAND reads that were not correctable by read retries, all levels of ECC, or XOR (as applicable)\&. 8 bytes

T}

T{

.sp

\fBSoft ECC Error Count\fR

T}:T{

.sp

Total count of NAND reads that were not correctable by read retries, or first\-level ECC\&. 8 bytes

T}

T{

.sp

\fBSSD End to End Detection Count\fR

T}:T{

.sp

A count of the detected errors by the SSD end to end error correction which includes DRAM, SRAM, or other storage element ECC/CRC protection mechanism (not NAND ECC)\&. 4 bytes

T}

T{

.sp

\fBSSD End to End Correction Count\fR

T}:T{

.sp

A count of the corrected errors by the SSD end to end error correction which includes DRAM, SRAM, or other storage element ECC/CRC protection mechanism (not NAND ECC)\&. 4 bytes

T}

T{

.sp

\fBSystem Data % Used\fR

T}:T{

.sp

A normalized cumulative count of the number of erase cycles per block since leaving the factory for the system (FW and metadata) area\&. Starts at 0 and increments\&. 100 indicates that the estimated endurance has been consumed\&.

T}

T{

.sp

\fBUser Data Max Erase Count\fR

T}:T{

.sp

The maximum erase count across all NAND blocks in the drive\&. 4 bytes

T}

T{

.sp

\fBUser Data Min Erase Count\fR

T}:T{

.sp

The minimum erase count across all NAND blocks in the drive\&. 4 bytes

T}

T{

.sp

\fBRefresh Count\fR

T}:T{

.sp

A count of the number of blocks that have been re\-allocated due to background operations only\&. 8 bytes

T}

T{

.sp

\fBProgram Fail Count\fR

T}:T{

.sp

Raw and normalized count of total program failures\&. Normalized count starts at 100 and shows the percent of remaining allowable failures\&. 2 bytes normalized, 6 bytes raw count

T}

T{

.sp

\fBUser Data Erase Fail Count\fR

T}:T{

.sp

Raw and normalized count of total erase failures in the user area\&. Normalized count starts at 100 and shows the percent of remaining allowable failures\&. 2 bytes normalized, 6 bytes raw count

T}

T{

.sp

\fBSystem Area Erase Fail Count\fR

T}:T{

.sp

Raw and normalized count of total erase failures in the system area\&. Normalized count starts at 100 and shows the percent of remaining allowable failures\&. 2 bytes normalized, 6 bytes raw count

T}

T{

.sp

\fBThermal Throttling Status\fR

T}:T{

.sp

The current status of thermal throttling (enabled or disabled)\&. 2 bytes

T}

T{

.sp

\fBThermal Throttling Count\fR

T}:T{

.sp

A count of the number of thermal throttling events\&. 2 bytes

T}

T{

.sp

\fBPCIe Correctable Error Count\fR

T}:T{

.sp

Summation counter of all PCIe correctable errors (Bad TLP, Bad DLLP, Receiver error, Replay timeouts, Replay rollovers)\&. 8 bytes

T}

.TE

.sp 1

.SH "C1 LOG PAGE DATA OUTPUT EXPLANATION"

.TS

allbox tab(:);

ltB ltB.

T{

Field

T}:T{

Description

T}

.T&

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt

lt lt.

T{

.sp

\fBHost Read Commands\fR

T}:T{

.sp

Number of host read commands received during the reporting period\&.

T}

T{

.sp

\fBHost Read Blocks\fR

T}:T{

.sp

Number of 512\-byte blocks requested during the reporting period\&.

T}

T{

.sp

\fBAverage Read Size\fR

T}:T{

.sp

Average Read size is calculated using (Host Read Blocks/Host Read Commands)\&.

T}

T{

.sp

\fBHost Read Cache Hit Commands\fR

T}:T{

.sp

Number of host read commands that serviced entirely from the on\-board read cache during the reporting period\&. No access to the NAND flash memory was required\&. This count is only updated if the entire command was serviced from the cache memory\&.

T}

T{

.sp

\fBHost Read Cache Hit Percentage\fR

T}:T{

.sp

Percentage of host read commands satisfied from the cache\&.

T}

T{

.sp

\fBHost Read Cache Hit Blocks\fR

T}:T{

.sp

Number of 512\-byte blocks of data that have been returned for Host Read Cache Hit Commands during the reporting period\&. This count is only updated with the blocks returned for host read commands that were serviced entirely from cache memory\&.

T}

T{

.sp

\fBAverage Read Cache Hit Size\fR

T}:T{

.sp

Average size of read commands satisfied from the cache\&.

T}

T{

.sp

\fBHost Read Commands Stalled\fR

T}:T{

.sp

Number of host read commands that were stalled due to a lack of resources within the SSD during the reporting period (NAND flash command queue full, low cache page count, cache page contention, etc\&.)\&. Commands are not considered stalled if the only reason for the delay was waiting for the data to be physically read from the NAND flash\&. It is normal to expect this count to equal zero on heavily utilized systems\&.

T}

T{

.sp

\fBHost Read Commands Stalled Percentage\fR

T}:T{

.sp

Percentage of read commands that were stalled\&. If the figure is consistently high, then consideration should be given to spreading the data across multiple SSDs\&.

T}

T{

.sp

\fBHost Write Commands\fR

T}:T{

.sp

Number of host write commands received during the reporting period\&.

T}

T{

.sp

\fBHost Write Blocks\fR

T}:T{

.sp

Number of 512\-byte blocks written during the reporting period\&.

T}

T{

.sp

\fBAverage Write Size\fR

T}:T{

.sp

Average Write size calculated using (Host Write Blocks/Host Write Commands)\&.

T}

T{

.sp

\fBHost Write Odd Start Commands\fR

T}:T{

.sp

Number of host write commands that started on a non\-aligned boundary during the reporting period\&. The size of the boundary alignment is normally 4K; therefore this returns the number of commands that started on a non\-4K aligned boundary\&. The SSD requires slightly more time to process non\-aligned write commands than it does to process aligned write commands\&.

T}

T{

.sp

\fBHost Write Odd Start Commands Percentage\fR

T}:T{

.sp

Percentage of host write commands that started on a non\-aligned boundary\&. If this figure is equal to or near 100%, and the NAND Read Before Write value is also high, then the user should investigate the possibility of offsetting the file system\&. For Microsoft Windows systems, the user can use Diskpart\&. For Unix\-based operating systems, there is normally a method whereby file system partitions can be placed where required\&.

T}

T{

.sp

\fBHost Write Odd End Commands\fR

T}:T{

.sp

Number of host write commands that ended on a non\-aligned boundary during the reporting period\&. The size of the boundary alignment is normally 4K; therefore this returns the number of commands that ended on a non\-4K aligned boundary\&.

T}

T{

.sp

\fBHost Write Odd End Commands Percentage\fR

T}:T{

.sp

Percentage of host write commands that ended on a non\-aligned boundary\&.

T}

T{

.sp

\fBHost Write Commands Stalled\fR

T}:T{

.sp

Number of host write commands that were stalled due to a lack of resources within the SSD during the reporting period\&. The most likely cause is that the write data was being received faster than it could be saved to the NAND flash memory\&. If there was a large volume of read commands being processed simultaneously, then other causes might include the NAND flash command queue being full, low cache page count, or cache page contention, etc\&. It is normal to expect this count to be non\-zero on heavily utilized systems\&.

T}

T{

.sp

\fBHost Write Commands Stalled Percentage\fR

T}:T{

.sp

Percentage of write commands that were stalled\&. If the figure is consistently high, then consideration should be given to spreading the data across multiple SSDs\&.

T}

T{

.sp

\fBNAND Read Commands\fR

T}:T{

.sp

Number of read commands issued to the NAND devices during the reporting period\&. This figure will normally be much higher than the host read commands figure, as the data needed to satisfy a single host read command may be spread across several NAND flash devices\&.

T}

T{

.sp

\fBNAND Read Blocks\fR

T}:T{

.sp

Number of 512\-byte blocks requested from NAND flash devices during the reporting period\&. This figure would normally be about the same as the host read blocks figure

T}

T{

.sp

\fBAverage NAND Read Size\fR

T}:T{

.sp

Average size of NAND read commands\&.

T}

T{

.sp

\fBNAND Write Commands\fR

T}:T{

.sp

Number of write commands issued to the NAND devices during the reporting period\&. There is no real correlation between the number of host write commands issued and the number of NAND Write Commands\&.

T}

T{

.sp

\fBNAND Write Blocks\fR

T}:T{

.sp

Number of 512\-byte blocks written to the NAND flash devices during the reporting period\&. This figure would normally be about the same as the host write blocks figure\&.

T}

T{

.sp

\fBAverage NAND Write Size\fR

T}:T{

.sp

Average size of NAND write commands\&. This figure should never be greater than 128K, as this is the maximum size write that is ever issued to a NAND device\&.

T}

T{

.sp

\fBNAND Read Before Write\fR

T}:T{

.sp

This is the number of read before write operations that were required to process non\-aligned host write commands during the reporting period\&. See Host Write Odd Start Commands and Host Write Odd End Commands\&. NAND Read Before Write operations have a detrimental effect on the overall performance of the device\&.

T}

.TE

.sp 1

.SH "EXAMPLES"

.sp

.RS 4

.ie n \{\

\h'-04'\(bu\h'+03'\c

.\}

.el \{\

.sp -1

.IP \(bu 2.3

.\}

Has the program issue WDC smart\-add\-log Vendor Unique Command with default interval (14) :

.sp

.if n \{\

.RS 4

.\}

.nf

# nvme wdc smart\-add\-log /dev/nvme0

.fi

.if n \{\

.RE

.\}

.RE

.SH "NVME"

.sp

Part of the nvme\-user suite\&.