检测oracle数据库坏块的方法
检测oracle数据库坏块的办法:
1、使用DBV(DB File Verify)工具;
2、使用RMAN(Recovery Manager)工具;
DBV(DB File Verify)工具:
外部命令,物理介质数据结构完整性检查;
只能用于数据文件(offline或online),不支持控制文件和重做日志文件的块检查;
也可以验证备份文件(rman的copy命令备份或操作系统CP命令备份);
进入盘符,然后执行以下脚本:
D:\app\Administrator\oradata\orcl>dbv file=ZL9MTLBASE.DBF blocksize=8192;
RMAN(Recovery Manager)工具:
逻辑数据结构完整性检查;
在线使用Recovery Manager扫描坏块和备份时,需要数据库运行在归档模式(archive log),否则只能在数据库未打开(mount)的情况下进行;
RMAN>backup check logical validate datafile n ;
以上命令可以检查数据文件是否包含坏块,同时并不产生实际的备份输出。
而且当使用Recovery Manager进行实际的数据库备份时,同时也就进行了坏块检查。
直接使用RMAN的命令:backup validate check logical database;
结合V$DATABASE_BLOCK_CORRUPTION视图更方便。
1)、rman target / nocatalog
2)、RMAN> spool log to 'd:/dbbak/rmanlog.log';---指定输出rman日志文件
RMAN> run { allocate channel d1 type disk; allocate channel d2 type disk; allocate channel d3 type disk; allocate channel d4 type disk; backup validate check logical database; };
3)、select * from V$DATABASE_BLOCK_CORRUPTION;
4) 、--If V$DATABASE_BLOCK_CORRUPTION contains rows please run this query to find the objects that contains the corrupted blocks:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
SELECT e.owner, e.segment_type, e.segment_name, e.partition_name, c.file#, greatest(e.block_id, c.block#) corr_start_block#, least(e.block_id + e.blocks - 1, c.block# + c.blocks - 1) corr_end_block#, least(e.block_id + e.blocks - 1, c.block# + c.blocks - 1) - greatest(e.block_id, c.block#) + 1 blocks_corrupted, null description FROM dba_extents e, v$database_block_corruption c WHERE e.file_id = c.file# AND e.block_id <= c.block# + c.blocks - 1 AND e.block_id + e.blocks - 1 >= c.block# UNION SELECT s.owner, s.segment_type, s.segment_name, s.partition_name, c.file#, header_block corr_start_block#, header_block corr_end_block#, 1 blocks_corrupted, 'Segment Header' description FROM dba_segments s, v$database_block_corruption c WHERE s.header_file = c.file# AND s.header_block between c.block# and c.block# + c.blocks - 1 UNION SELECT null owner, null segment_type, null segment_name, null partition_name, c.file#, greatest(f.block_id, c.block#) corr_start_block#, least(f.block_id + f.blocks - 1, c.block# + c.blocks - 1) corr_end_block#, least(f.block_id + f.blocks - 1, c.block# + c.blocks - 1) - greatest(f.block_id, c.block#) + 1 blocks_corrupted, 'Free Block' description FROM dba_free_space f, v$database_block_corruption c WHERE f.file_id = c.file# AND f.block_id <= c.block# + c.blocks - 1 AND f.block_id + f.blocks - 1 >= c.block# order by file#, corr_start_block#;
5)、
SELECT tablespace_name, segment_type, owner, segment_name FROM dba_extents WHERE file_id = &fileid and &blockid between block_id AND block_id + blocks - 1;
告警日志中快速识别:
遇到坏块问题时,数据库的异常表现通常有:
报告ORA-01578错误。
报告ORA-1110错误。
报告ORA-00600错误。其中,第一个参数为2000-8000,Cache layer 2000 – 4000,Transaction layer 4000 – 6000,Data layer 6000 - 8000。
Trace文件中出现Corrupt block dba: 0x160c5958 . found。 分析对象失败。
后台进程,如DBWR,LGWR出现长时间异常等待,如LGWR wait for redo copy。