Adrian Klaver <adrian.klaver@xxxxxxxxxxx> writes: > On 6/8/20 7:33 PM, Peter wrote: >> That "cp" is usually not synchronous. So there is the possibility >> that this command terminates successfully, and reports exitcode zero >> back to the Postgres, and then the Postgres will consider that log >> being safely away. > Which is why just following the above command in the docs is: > "(This is an example, not a recommendation, and might not work on all > platforms.) " Yeah. There have been discussions about changing that disclaimer to be more forceful, because in point of fact a plain "cp" is generally not safe enough. You need to fsync the written file, and on many filesystems you also have to fsync the directory it's in. > Generally for peace of mind folks use third party tools like: +1. Rolling your own archive script is seldom advisable. regards, tom lane
