[smartmontools-support] nvme 'Data Units Read' and 'Data Units Written' question.

Christian Franke Christian.Franke at t-online.de
Sat Jun 29 18:37:44 CEST 2019

Robert Fantini wrote:
> Hello
> We just received a used INTEL 2TB Nvme .    Below is smartctl output.
> These are very high,   could the math be incorrect?
> Data Units Read:                    30,035,247,693 [15.3 PB]
> Data Units Written:                 11,932,680,343 [6.10 PB]

 From NVMe specs (same in 1.0 to 1.4):
"Data Units Read: Contains the number of 512 byte data units the host 
has read from the controller... This value is reported in thousands 
(i.e., a value of 1 corresponds to 1,000 units of 512 bytes read) ..."

Math looks good:

$ echo 'scale=1; 30035247693 * 512 * 1000 / (1000^5)' | bc

To check whether smartctl interprets raw data correctly, please provide 
output of
   smartctl -r ioctl,2 -i -A /dev/nvme0
as an attachment.


> PS: thank you for the great tool.
PS: You're welcome.

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