index f98417d283f30906b156660ce8b23ff5dd5834ce..2707e184b2c81e04c46b135533b42bcb742e74f7 100644 (file)
-<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.144 2010年02月22日 17:15:10 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/backup.sgml,v 2.145 2010年03月31日 23:35:19 momjian Exp $ -->
<chapter id="backup">
<title>Backup and Restore</title>
@@ -604,11 +604,12 @@ cp -i pg_xlog/00000001000000A900000065 /mnt/server/archivedir/00000001000000A900
directory).
It is advisable to test your proposed archive command to ensure that it
indeed does not overwrite an existing file, <emphasis>and that it returns
- nonzero status in this case</>. We have found that <literal>cp -i</> does
- this correctly on some platforms but not others. If the chosen command
- does not itself handle this case correctly, you should add a command
- to test for existence of the archive file. For example, something
- like:
+ nonzero status in this case</>. On many Unix platforms, <command>cp
+ -i</> causes copy to prompt before overwriting a file, and
+ <literal>< /dev/null</> causes the prompt (and overwriting) to
+ fail. If your platform does not support this behavior, you should
+ add a command to test for the existence of the archive file. For
+ example, something like:
<programlisting>
archive_command = 'test ! -f .../%f && cp %p .../%f'
</programlisting>