3 facts filed under FTL mapping: all 3 were read in the original source. Each was checked against the source’s own words, so its figures appear there, and each names where it comes from. The idea is taught in Part 6, The Flash Translation Layer.
Primary sources
In the NVMe NVM Command Set, after a write command has completed without error, later reads of that location must return the data that write wrote and not an older version of the data, with one stated exception.
In the NVMe NVM Command Set, a write with Force Unit Access set makes the controller write the data and metadata to non-volatile media before it indicates command completion, with no implied ordering with other commands.
In the Linux block layer, a write marked FUA (Force Unit Access) completes only after its data is committed to non-volatile storage, while a preflush request first empties the device’s volatile write cache; filesystems may set both on one request.
Sources
Primary is the original paper, standard or datasheet. Secondary is a review, a vendor summary or a news report. Measured is my own test data.
Show all 2 sources, 2 primary
- PrimaryNVM Express NVM Command Set Specification, Revision 1.0dNVM Express, Inc., 2023
- PrimaryExplicit volatile write back cache control — The Linux Kernel documentationdocs.kernel.org