Yes, that does allow you to copy the database directory with the "cp" command. The command tells postgres to stop deleting obsolete WAL files until further noti

Yes, that does allow you to copy the database directory with the "cp" command. The command tells postgres to stop deleting obsolete WAL files until further notice. As long as you start your copy after you issue the command, and copy across at least all of the files that are present (as in, you can ignore new files that are created), then the data is safe. Just don't forget to tell postgres that the backup has finished afterwards.