2015-06-18 0:53 GMT+05:30 Theo de Raadt <dera...@cvs.openbsd.org>: > > 2) General on SSD: When an SSD starts to shrink because it starts to wear > > out, how is this handled and how does this appear to the OS, logs, and > > system software? > > Invisible. Even when a few drives make it visible in some way, it is > highly proprietary. >
What is then proper behavior for a program or system using an SSD, to deal with SSD degradation?: So say you have a program altering a file's contents all the time, or you have file turnover on a system (rm f123; echo importantdata > f124). At some point the SSD will shrink and down the line reach zero capacity. The degradation process will be such that there will be no file content loss as long as the shrinking doesn't exceed the FS total files size right? (Spontaneously I'd presume the SSD informs the OS of shrinking at sector write time through failing sector writes, and the OS registers shrunk parts in the FS as broken sectors.) Will the SSD+OS reflect the degradation status in getfsstat(2) f_blocks / df(1) blocks so the program just ensure there's some f_bavail / avail all the time by simply shrinking (ftruncate etc.) its files accordingly and when f_blocks is too small shuts down completely? 3) On OBSD, how would you generally suggest to make a magnet-SSD hybrid disk setup where the SSD gives the speed and maget storage security?
