if no wal, the backup need flush before backup which may cost time, so we use the wal
if no wal, the backup need flush before backup which may cost time, so we use the wal

absolute8511/ZanRedisDB,absolute8511/ZanRedisDB,absolute8511/ZanRedisDB,absolute8511/ZanRedisDB,absolute8511/ZanRedisDB,absolute8511/ZanRedisDB,absolute8511/ZanRedisDB