On Thu, Jan 20, 2011 at 12:42, Magnus Hagander <mag...@hagander.net> wrote: > On Thu, Jan 20, 2011 at 05:23, Fujii Masao <masao.fu...@gmail.com> wrote: >> It's helpful to document what to set to allow pg_basebackup connection. >> That is not only the REPLICATION privilege but also max_wal_senders and >> pg_hba.conf. > > Hmm. Yeha, i guess that wouldn't hurt. Will add that.
Added, see github branch. >> + <refsect1> >> + <title>Options</title> >> >> Can we list the descriptions of option in the same order as >> "pg_basebackup --help" does? >> >> It's helpful to document that the target directory must be specified and >> it must be empty. > > Yeah, that's on the list - I just wanted to make any other changes > first before I did that. I based on (no further) feedback and a few > extra questions, I'm going to change it per your suggestion to use -D > <dir> -F <format>, instead of -D/-T, which will change that stuff > anyway. So I'll reorder them at that time. Updated on github. >> + <para> >> + The backup will include all files in the data directory and tablespaces, >> + including the configuration files and any additional files placed in the >> + directory by third parties. Only regular files and directories are >> allowed >> + in the data directory, no symbolic links or special device files. >> >> The latter sentence means that the backup of the database cluster >> created by initdb -X is not supported? Because the symlink to the >> actual WAL directory is included in it. > > No, it's not. pg_xlog is specifically excluded, and sent as an empty > directory, so upon restore you will have an empty pg_xlog directory. Actually, when I verified that statement, I found a bug where we sent the wrong thing if pg_xlog was a symlink, leading to a corrupt tarfile! Patch is in the github branch. >> OTOH, I found the following source code comments: >> >> + * Receive a tar format stream from the connection to the server, and unpack >> + * the contents of it into a directory. Only files, directories and >> + * symlinks are supported, no other kinds of special files. >> >> This says that symlinks are supported. Which is true? Is the symlink >> supported only in tar format? > > That's actually a *backend* side restriction. If there is a symlink > anywhere other than pg_tblspc in the data directory, we simply won't > send it across (with a warning). > > The frontend code supports creating symlinks, both in directory format > and in tar format (actually, in tar format it doesn't do anything, of > course, it just lets it through) > > It wouldn't actually be hard to allow the inclusion of symlinks in the > backend side. But it would make verification a lot harder - for > example, if someone symlinked out pg_clog (as an example), we'd back > up the symlink but not the actual files since they're not actually > registered as a tablespace. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
