On Tue, Jun 9, 2015 at 9:09 AM, Fujii Masao <masao.fu...@gmail.com> wrote: > > On Tue, May 12, 2015 at 10:42 PM, Andrew Dunstan <and...@dunslane.net> wrote: > > Map basebackup tablespaces using a tablespace_map file > > > > Windows can't reliably restore symbolic links from a tar format, so > > instead during backup start we create a tablespace_map file, which is > > used by the restoring postgres to create the correct links in pg_tblspc. > > The backup protocol also now has an option to request this file to be > > included in the backup stream, and this is used by pg_basebackup when > > operating in tar mode. > > > > This is done on all platforms, not just Windows. > > > > This means that pg_basebackup will not not work in tar mode against 9.4 > > and older servers, as this protocol option isn't implemented there. > > While I was performing the recovery-related tests, I found that there was > the case where $PGDATA/tablespace_map was not renamed to *.old at the recovery. > Is this harmless and intentional?
There shouldn't be any problem because we tablespace_map file only if backup file is present. > Sorry if this has been already > discussed so far. > > The steps to reproduce the problem is: > > 1. start base backup, i.e., call pg_start_backup(). > 2. repeat some write transactions and checkpoints until the WAL file containing > the checkpoint record that backup_label indicates will be removed. > 3. killall -9 postgres > 4. start the server and a crash recovery. > > At this time, the crash recovery fails with the following error messages. > 2015-06-09 12:26:54 JST FATAL: could not locate required checkpoint record > 2015-06-09 12:26:54 JST HINT: If you are not restoring from a backup, > try removing the file ".../backup_label". > > 5. according to the above hint message, remove $PGDATA/backup_label > and restart a crash recovery > > Then you can see that tablespace_map remains in $PGDATA after the recovery ends. > The basic idea is that tablespace_map file will be used in case we have to restore from a backup which contains tablespaces. So I think if user is manually removing backup_label, there is no meaning of tablespace_map, so that should also be removed. One way to address this is modify the Hint message suggesting that remove tablespace_map if present. Current : If you are not restoring from a backup, try removing the file \"%s/backup_label\ Modify it to: If you are not restoring from a backup, try removing the file \"%s/backup_label\ and, if present \"%s/tablespace_map\. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
