On Fri, 2019-07-12 at 12:00 +0900, Damien Le Moal wrote: > zonefs is a very simple file system exposing each zone of a zoned > block device as a file. This is intended to simplify implementation As far as I can see, a zone usually is pretty big in size (for example, 256MB). But [1, 2] showed that about 60% of files on a file system volume has size about 4KB - 128KB. Also [3] showed that modern application uses a very complex files' structures that are updated in random order. Moreover, [4] showed that 90% of all files are not used after initial creation, those that are used are normally short-lived, and that if a file is not used in some manner the day after it is created, it will probably never be used; 1% of all files are used daily. It sounds for me that mostly this approach will lead to waste of zones' space. Also, the necessity to update data of the same file will be resulted in frequent moving of files' data from one zone to another one. If we are talking about SSDs then it sounds like quick and easy way to kill this device fast. Do you have in mind some special use-case? Thanks, Viacheslav Dubeyko. [1] Agrawal, et al., “A Five-Year Study of File-System Metadata,” ACM Transactions on Storage (TOS), vol. 3 Issue 3, Oct. 2007, Article No. 9. [2] Douceur, et al., “A Large-Scale Study of File-System Contents,” SIGMETRICS '99 Proceedings of the 1999 ACM SIGMETRICS international conference on Measurement and modeling of computer systems, pp. 59-70, May 1-4, 1999. [3] Tyler Harter, Chris Dragga, Michael Vaughn, Andrea C. Arpaci- Dusseau, and Remzi H. Arpaci-Dusseau, “A file is not a file: understanding the I/O behavior of Apple desktop applications.” In Proceedings of the Twenty-Third ACM Symposium on Operating Systems Principles (SOSP '11). ACM, New York, NY, USA, 71-83. [4] Tim Gibson, Ethan L. Miller, Darrell D. E. Long, “Long-term File Activity and Inter-Reference Patterns.”
