Luis, > Applications which want to support ZNS have to take into consideration > that NPO2 is posisble and there existing users of that world today. Every time a new technology comes along vendors inevitably introduce first gen devices that are implemented with little consideration for the OS stacks they need to work with. This has happened for pretty much every technology I have been involved with over the years. So the fact that NPO2 devices exist is no argument. There are tons of devices out there that Linux does not support and never will. In early engagements SSD drive vendors proposed all sorts of weird NPO2 block sizes and alignments that it was argued were *incontestable* requirements for building NAND devices. And yet a generation or two later every SSD transparently handled 512-byte or 4096-byte logical blocks just fine. Imagine if we had re-engineered the entire I/O stack to accommodate these awful designs? Similarly, many proponents suggested oddball NPO2 sizes for SMR zones. And yet the market very quickly settled on PO2 once things started shipping in volume. Simplicity and long term maintainability of the kernel should always take precedence as far as I'm concerned. -- Martin K. Petersen Oracle Linux Engineering
