Hi André, > On 01. May, 2020, at 12:47, André Hänsel <andre@xxxxxxxx> wrote: > > I知 using pgBackRest for incremental backups which, as far as I understand, > use the WAL. These backups are relatively large, so I wanted to take a look > at my WAL. I understand pg_waldump is the tool for this. > > However, I struggle with its usage. > > The --help output suggests all command line parameters are optional, but > running it like that yields "pg_waldump: no arguments specified". So I tried > "pg_waldump -z" which yields "pg_waldump: FATAL: could not find any WAL > file". Ok, so apparently it doesn't know the location of the WAL files. I > then tried "pg_waldump -p /var/lib/postgresql/11/main/pg_wal". > > Now I get "pg_waldump: no start WAL location given". And this is where I'm > stuck. I don't know any WAL location. I don't even know how far back my WAL > goes, that's one thing I want to find out, among other things. > > On https://www.postgresql.org/docs/11/pgwaldump.html it says about > "--start": >> WAL location at which to start reading. The default is to start reading > the first valid log record found in the earliest file found. > > If that's the default, why does it ask me for a WAL location? > > What do I need to do? try: pg_waldump -p /var/lib/postgresql/11/main/pg_wal <start-wal> [<end-wal>] where <start-wal> is the name of the WAL file to start and (optionally) <end-wal> is the WAL file to stop. It reads and shows all information of the WAL files in this range. Hope, this helps. Cheers, Paul
