一次简单的Oracle恢复Case实战记录

发现问题

某网友的数据库由于坏盘了，并且存储掉电，导致数据库无法open了。单看其数据库alert log的错误来看，是非常之简单的，如下:

fri oct 26 10:33:53 2018
recovery of online redo log: thread 1 group 3 seq 39 reading mem 0
mem# 0: /fs/fs/oradata/orcl/redo03.log
block recovery stopped at eot rba 39.77.16
block recovery completed at rba 39.77.16, scn 0.1002048587
oracle instance orcl (pid = 8) - error 600 encountered while recovering transaction (9, 30) on object 9149.
fri oct 26 10:33:53 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_smon_192644.trc:
ora-00600: internal error code, arguments: [6856], [0], [43], [], [], [], [], []
fri oct 26 10:33:56 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_smon_192644.trc:
ora-00600: internal error code, arguments: [4194], [33], [36], [], [], [], [], []
doing block recovery for file 2 block 713
block recovery from logseq 39, block 82 to scn 1002048595

对于这种错误，很明显，屏蔽回滚段即可，屏蔽之后可顺利打开数据库，不过后面很快又会crash掉，因此重建undo也就绕过这个问题了。

打开数据库之后，再去观察数据库，会发现alert log有不少的错误，如下所示：

fri oct 26 11:01:46 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_mmon_385148.trc:
ora-00600: internal error code, arguments: [17147], [0x110549070], [], [], [], [], [], []
fri oct 26 11:01:46 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_m001_373218.trc:
ora-00600: internal error code, arguments: [kdddgb5], [196650], [0], [], [], [], [], []
ora-600 encountered when generating server alert smg-4120
fri oct 26 11:01:47 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_mmon_385148.trc:
ora-00600: internal error code, arguments: [kghalo4], [0x11047f6f0], [], [], [], [], [], []
ora-600 encountered when generating server alert smg-4121
fri oct 26 11:01:48 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_mmon_385148.trc:
ora-00600: internal error code, arguments: [kghalo4], [0x11047f6f0], [], [], [], [], [], []
ora-600 encountered when generating server alert smg-4121
fri oct 26 11:01:50 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_m001_373218.trc:
ora-00600: internal error code, arguments: [kdddgb5], [196650], [0], [], [], [], [], []
fri oct 26 11:02:22 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_mmon_385148.trc:
ora-00600: internal error code, arguments: [17114], [0x110549070], [], [], [], [], [], []
fri oct 26 11:02:23 2018
errors in file /fs/fs/oradata/admin/orcl/bdump/orcl_mmon_385148.trc:
ora-00600: internal error code, arguments: [kebm_mmon_main_1], [39], [], [], [], [], [], []
ora-00039: error during periodic action
ora-00600: internal error code, arguments: [17114], [0x110549070], [], [], [], [], [], []
fri oct 26 11:03:30 2018
restarting dead background process mmon

除此之外，由于之外alert log有坏块报错，因此对system进行了dbv检查，发现确实存在少量坏块，如下：

dbverify: release 10.2.0.4.0 - production on fri oct 26 10:37:20 2018
 
copyright (c) 1982, 2007, oracle. all rights reserved.
 
dbverify - verification starting : file = system01.dbf
 
dbv-00200: block, dba 4255202, already marked corrupt
block checking: dba = 4258751, block type = ktb-managed data block
data header at 0x11022a05c
kdbchk: fsbo(596) wrong, (hsz 4178)
page 64447 failed with check code 6129
block checking: dba = 4259386, block type = ktb-managed data block
**** kdxcofbo = 208 != 24
---- end index block validation
page 65082 failed with check code 6401
block checking: dba = 4269609, block type = unlimited data segment header
incorrect extent count in the extent map: 16777317
block checking: dba = 4269612, block type = ktb-managed data block
**** kdxcofbo = 224 != 216
---- end index block validation
page 75308 failed with check code 6401
block checking: dba = 4269615, block type = ktb-managed data block
**** actual rows locked by itl 2 = 1 != # in trans. header = 0
---- end index block validation
page 75311 failed with check code 6401
page 85271 is influx - most likely media corrupt
corrupt block relative dba: 0x00414d17 (file 1, block 85271)
fractured block found during dbv:
data in bad block:
type: 6 format: 2 rdba: 0x00414d17
last change scn: 0x0000.3afaf495 seq: 0x1 flg: 0x04
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0xfe830601
check value in block header: 0x96c6
computed block checksum: 0x3c6b
 
page 85383 is influx - most likely media corrupt
corrupt block relative dba: 0x00414d87 (file 1, block 85383)
fractured block found during dbv:
data in bad block:
type: 6 format: 2 rdba: 0x00414d87
last change scn: 0x0000.3b6b9d19 seq: 0x1 flg: 0x06
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x970f0601
check value in block header: 0xe825
computed block checksum: 0x3c6b
 
dbverify - verification complete
 
total pages examined : 640000
total pages processed (data) : 116312
total pages failing (data) : 1
total pages processed (index): 65914
total pages failing (index): 3
total pages processed (other): 64634
total pages processed (seg) : 0
total pages failing (seg) : 0
total pages empty : 393138
total pages marked corrupt : 3
total pages influx : 2
highest block scn : 1002028510 (0.1002028510)

这部分错误，其实处理起来也不困难，部分是业务表的index，但是其他的几乎都是awr相关基表，有2个坏块跟是system相关的基表和索引，分别是i_h_obj#_col#和com$ ，histgrm$。

对于业务索引，很简单，直接drop 重建即可，对于这个sys的index，可以通过设置38003 event进行drop重建。

对于基表com$,histgrm$，由于是非bootstrap$核心对象，其实也可以处理掉的。

处理方法

不过考虑到这种毕竟是存储掉电，undo异常的情况，还是重建库更稳妥一些。最后补充一点，这个库稍微有点奇葩的地方是全库1.2tb，其中有个表的lob自动980gb，重建数据库是相对较慢的。对于大表，且有lob自动，通常建议基于分片，否则会报ora-01555错误的，如下是常用的一个基于rowid的分片脚本，供大家参考：

set verify off
 
undefine rowid_ranges
 
undefine segment_name
 
undefine owner
 
set head off
 
set pages 0
 
set trimspool on
 
select 'where rowid between ''' ||
 
  sys.dbms_rowid.rowid_create(1, d.oid, c.fid1, c.bid1, 0) ||
 
  ''' and ''' ||
 
  sys.dbms_rowid.rowid_create(1, d.oid, c.fid2, c.bid2, 9999) || '''' || ';'
 
 from (select distinct b.rn,
 
      first_value(a.fid) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) fid1,
 
      last_value(a.fid) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) fid2,
 
      first_value(decode(sign(range2 - range1),
 
           1,
 
           a.bid +
 
           ((b.rn - a.range1) * a.chunks1),
 
           a.bid)) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) bid1,
 
      last_value(decode(sign(range2 - range1),
 
           1,
 
           a.bid +
 
           ((b.rn - a.range1 + 1) * a.chunks1) - 1,
 
           (a.bid + a.blocks - 1))) over(partition by b.rn order by a.fid, a.bid rows between unbounded preceding and unbounded following) bid2
 
   from (select fid,
 
      bid,
 
      blocks,
 
      chunks1,
 
      trunc((sum2 - blocks + 1 - 0.1) / chunks1) range1,
 
      trunc((sum2 - 0.1) / chunks1) range2
 
     from (select /*+ rule */
 
       relative_fno fid,
 
       block_id bid,
 
       blocks,
 
       sum(blocks) over() sum1,
 
       trunc((sum(blocks) over()) / &&rowid_ranges) chunks1,
 
       sum(blocks) over(order by relative_fno, block_id) sum2
 
       from dba_extents
 
       where segment_name = upper('&&segment_name')
 
       and owner = upper('&&owner'))
 
     where sum1 > &&rowid_ranges) a,
 
    (select rownum - 1 rn
 
     from dual
 
    connect by level <= &&rowid_ranges) b
 
   where b.rn between a.range1 and a.range2) c,
 
  (select max(data_object_id) oid
 
   from dba_objects
 
   where object_name = upper('&&segment_name')
 
   and owner = upper('&&owner')
 
   and data_object_id is not null) d
 
/

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，如果有疑问大家可以留言交流，谢谢大家对的支持。