Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 4C0289FB8BC for ; Mon, 7 May 2007 15:58:15 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 02569-03 for ; Mon, 7 May 2007 15:58:09 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from serv01.siteground137.com (ns1.siteground137.com [67.15.250.10]) by postgresql.org (Postfix) with ESMTP id 5DF1A9FB7E3 for ; Mon, 7 May 2007 15:58:11 -0300 (ADT) Received: from nat.vinton.com ([209.162.219.253]:57237 helo=dogma.v10.wvs) by serv01.siteground137.com with esmtpa (Exim 4.52) id 1Hl8PN-0000XB-1L for pgsql-general@postgresql.org; Mon, 07 May 2007 13:58:05 -0500 Subject: PITR and tar From: Jeff Davis To: pgsql-general@postgresql.org Content-Type: text/plain Date: Mon, 07 May 2007 11:58:06 -0700 Message-Id: <1178564286.23358.7.camel@dogma.v10.wvs> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-7) Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - serv01.siteground137.com X-AntiAbuse: Original Domain - postgresql.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - j-davis.com X-Source: X-Source-Args: X-Source-Dir: X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/294 X-Sequence-Number: 113489 The docs recommend using tar to perform a base backup for PITR. Usually, tar reports notices like: "tar: Truncated write; file may have grown while being archived." First of all, is the tar archive still safe if those errors occur? Second, it seems that it can cause a bad backup to occur if you pass the "z" option to tar. Instead, piping the output of tar through the compression program seems to avoid that problem (i.e. "tar cf - ... | gzip > ..."). I am using FreeBSD's tar, other implementations may be different. Are my observations correct, and if so, should they be documented as a potential "gotcha" when making base backups? Regards, Jeff Davis