Category Archives: Oracle备份恢复

找回ASM中数据文件

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很多时候由于asm不能正常启动，导致数据丢失。下面提供两种方法找回asm中的数据文件
一.使用AMDU工具
AMDU是Oracle 11g里自带的一个免费的工具，用于分析ASM磁盘组的元数据以及从不能mount的磁盘组中往外抽取数据文件“NOTE:553639.1 Placeholder for AMDU binaries and using with ASM 10g”明确指出：AMDU也可用于10g，并提供了可用于10g的AMDU的各个操作系统的版本供大家下载。
1.设置LD_LIBRARY_PATH

rac1-> export LD_LIBRARY_PATH=/tmp/amdu

2.查看asm磁盘信息

rac1-> ./amdu -diskstring '/dev/raw/raw*'  
amdu_2012_03_05_03_17_19/
rac1-> cd amdu_2012_03_05_03_17_19/
rac1-> ls
report.txt
rac1-> more report.txt 
-*-amdu-*-

******************************* AMDU Settings ********************************
ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1
System name:    Linux
Node name:      rac1
Release:        2.6.9-89.0.0.0.1.ELhugemem
Version:        #1 SMP Tue May 19 04:38:38 EDT 2009
Machine:        i686
amdu run:       05-MAR-12 03:17:19
Endianess:      1

--------------------------------- Operations ---------------------------------

------------------------------- Disk Selection -------------------------------
 -diskstring '/dev/raw/raw*'

------------------------------ Reading Control -------------------------------

------------------------------- Output Control -------------------------------

********************************* DISCOVERY **********************************

----------------------------- DISK REPORT N0001 ------------------------------
                Disk Path: /dev/raw/raw23
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0002 ------------------------------
                Disk Path: /dev/raw/raw11
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0003 ------------------------------
                Disk Path: /dev/raw/raw32
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0004 ------------------------------
                Disk Path: /dev/raw/raw31
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0005 ------------------------------
                Disk Path: /dev/raw/raw12
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 156 megabytes
** NOT A VALID ASM DISK HEADER. BAD VALUE IN FIELD blksize_kfdhdb **

----------------------------- DISK REPORT N0006 ------------------------------
                Disk Path: /dev/raw/raw2
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 1976 megabytes
               Group Name: DATA
                Disk Name: DATA_0001
       Failure Group Name: DATA_0001
              Disk Number: 1
            Header Status: 3
       Disk Creation Time: 2012/03/01 22:32:39.289000
          Last Mount Time: 2012/03/05 02:10:02.771000
    Compatibility Version: 0x0a100000
         Disk Sector Size: 512 bytes
         Disk size in AUs: 1976 AUs
         Group Redundancy: 1
      Metadata Block Size: 4096 bytes
                  AU Size: 1048576 bytes
                   Stride: 113792 AUs
      Group Creation Time: 2012/03/01 22:32:39.221000
  File 1 Block 1 location: AU 0

----------------------------- DISK REPORT N0007 ------------------------------
                Disk Path: /dev/raw/raw1
           Unique Disk ID: 
               Disk Label: 
     Physical Sector Size: 512 bytes
                Disk Size: 3137 megabytes
               Group Name: DATA
                Disk Name: DATA_0000
       Failure Group Name: DATA_0000
              Disk Number: 0
            Header Status: 3
       Disk Creation Time: 2012/03/01 22:32:39.289000
          Last Mount Time: 2012/03/05 02:10:02.771000
    Compatibility Version: 0x0a100000
         Disk Sector Size: 512 bytes
         Disk size in AUs: 3137 AUs
         Group Redundancy: 1
      Metadata Block Size: 4096 bytes
                  AU Size: 1048576 bytes
                   Stride: 113792 AUs
      Group Creation Time: 2012/03/01 22:32:39.221000
  File 1 Block 1 location: AU 2

******************************* END OF REPORT ********************************

从这里可以得到信息如下：
1)只有/dev/raw/raw1和raw2是有效的asm磁盘
2)磁盘组只有DATA

3.找出数据文件信息

rac1-> ../amdu -diskstring '/dev/raw/raw*'  -dump 'DATA'
amdu_2012_03_05_03_19_38/
rac1-> cd amdu_2012_03_05_03_19_38/
rac1-> ls
DATA_0001.img  DATA.map  report.txt
rac1-> strings DATA_0001.img |grep DATAFILE
DATAFILE
DATAFILE
DATAFILE
DEVDB/DATAFILE/SYSTEM.256.776817753
DEVDB/DATAFILE/SYSAUX.257.776817753
DEVDB/DATAFILE/UNDOTBS1.258.776817753
DEVDB/DATAFILE/USERS.259.776817753
DEVDB/DATAFILE/UNDOTBS2.267.776817909

从这里可以得出数据文件的file号(第一位数字)

4.恢复数据文件

rac1-> ../../amdu -diskstring '/dev/raw/raw*' -extract 'DATA.259'
amdu_2012_03_05_03_27_21/
rac1-> cd amdu_2012_03_05_03_27_21/
rac1-> ls -l
total 5148
-rw-r--r--  1 oracle oinstall 5251072 Mar  5 03:27 DATA_259.f
-rw-r--r--  1 oracle oinstall    6468 Mar  5 03:27 report.txt
rac1-> dbv file=DATA_259.f

DBVERIFY: Release 10.2.0.1.0 - Production on Mon Mar 5 03:28:00 2012

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

DBVERIFY - Verification starting : FILE = DATA_259.f


DBVERIFY - Verification complete

Total Pages Examined         : 640
Total Pages Processed (Data) : 15
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 2
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 26
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 597
Total Pages Marked Corrupt   : 0
Total Pages Influx           : 0
Highest block SCN            : 442362 (0.442362)

二.使用aulasm工具
1.配置ASM使用磁盘

[root@rac1 oracle]# more disk
/dev/sdb1
/dev/sdb2

2.使用aulasm

[root@rac1 oracle]# ./aulasm_linux32_trial.bin 
AUL : AnySQL UnLoader(MyDUL) for Oracle ASM, release 2.0.0

(C) Copyright Lou Fangxin 2011-2012 (AnySQL.net), all rights reserved.

ASM> help
  SET        -- set options (BLOCK_SIZE, AU_SIZE, F1B1_DISK, F1B1_AU)
  OPEN       -- open data file
  ADD        -- add disk with customized disk num (disk, path)
  LIST       -- list opened disks information (to)
  LSAU       -- list file of given AU (disk, au, count)
  FILE       -- list all file entries in ASM (file, [disk, au, block]).
  ALIAS      -- list all alias entries in ASM (file, [disk, au, block]).
  EXTENT     -- list or adjust variable extent (level, au, count).
  FMAP       -- list file extent (file, [disk, au, block], to)
  DUMP       -- dump file extent (file, [disk, au, block], offset, to)
  COPY       -- copy file to os  (file, [disk, au, block], to)
  QUIT/EXIT  -- exit the program.
ASM> open disk
2012-03-05 03:32:48
2012-03-05 03:32:48
ASM> list
2012-03-05 03:32:49
Total Disks = 2, ausize=1048576, blksize=4096

 disk     size block disk name        disk group   disk path               
===== ======== ===== ================ ============ ========================
    0     3137  4096 DATA_0000        DATA         /dev/sdb1
    1     1976  4096 DATA_0001        DATA         /dev/sdb2

f1b1disk = 0, f1b1au = 2, score=256, compat=0x0a100000
file=(1,0,2,1), disk=(2,0,2,2), alias=(6,0,2,6)
2012-03-05 03:32:49
ASM> alias
2012-03-05 03:33:15
    file          inc parent fstblk flag  refer alias                     
======== ============ ====== ====== ==== ====== ==========================
      -1           -1      0      0    4      1 DEVDB
      -1           -1      0      1    4      2 DATAFILE
      -1           -1      0      1    4      3 CONTROLFILE
      -1           -1      0      1    4      4 ONLINELOG
      -1           -1      0      1    4      5 TEMPFILE
      -1           -1      0      1    4      6 PARAMETERFILE
      -1           -1      0      1    4      7 ARCHIVELOG
     256    776817753      1      2   18     -1 SYSTEM
     257    776817753      1      2   18     -1 SYSAUX
     258    776817753      1      2   18     -1 UNDOTBS1
     259    776817753      1      2   18     -1 USERS
     267    776817909      1      2   18     -1 UNDOTBS2
     261    776817829      1      3   18     -1 Current
     260    776817829      1      3   18     -1 Current
     262    776817833      1      4   18     -1 group_1
     263    776817835      1      4   18     -1 group_1
     264    776817837      1      4   18     -1 group_2
     265    776817841      1      4   18     -1 group_2
     268    776818011      1      4   18     -1 group_3
     269    776818013      1      4   18     -1 group_3
     270    776818015      1      4   18     -1 group_4
     271    776818017      1      4   18     -1 group_4
     266    776817859      1      5   18     -1 TEMP
     272    776818021      1      6   18     -1 spfile
      -1           -1      1      7    4      8 2012_03_01
      -1           -1      1      7    4      9 2012_03_03
      -1           -1      1      7    4     10 2012_03_05
     273    776818747      7      8   18     -1 thread_1_seq_2
     274    776819571      7      8   18     -1 thread_1_seq_3
     275    776819721      7      8   18     -1 thread_2_seq_1
     276    776820331      7      8   18     -1 thread_1_seq_4
     277    776992321      7      9   18     -1 thread_1_seq_5
     278    776992321      7      9   18     -1 thread_2_seq_2
     279    777089437      7     10   18     -1 thread_1_seq_6
2012-03-05 03:33:15
ASM> fmap file 259    
2012-03-05 03:34:49
fid=259, disk=0, au=56, block=3
siz=5, ecnt=6, eeof=6, flags=17, type=12, alias=109,-1
     extid  disk       auid  cnt flg chk
========== ===== ========== ==== === ===
         1     0        428    1   0 135
         2     1        408    1   0 178
         3     0        429    1   0 134
         4     1        409    1   0 179
         5     0        430    1   0 133
         6     1        410    1   0 176
2012-03-05 03:34:49
ASM> copy file 259 to user_259
2012-03-05 03:35:01
2012-03-05 03:35:01
[root@rac1 oracle]# ll
total 6252
-rwxr-xr-x  1 root   root       84619 Mar  6  2012 aulasm_linux32_trial.bin
-rw-r--r--  1 root   root          20 Mar  5 02:52 disk
-rw-r--r--  1 root   root     6291456 Mar  5 03:35 user_259
[root@rac1 oracle]# su - oracle
rac1-> dbv file=user_259 

DBVERIFY: Release 10.2.0.1.0 - Production on Mon Mar 5 03:35:27 2012

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

DBVERIFY - Verification starting : FILE = user_259


DBVERIFY - Verification complete

Total Pages Examined         : 640
Total Pages Processed (Data) : 15
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 2
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 26
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 597
Total Pages Marked Corrupt   : 0
Total Pages Influx           : 0
Highest block SCN            : 442362 (0.442362)

通过dbv验证，两个数据文件(文件大小有出入，可能在对待未格式化数据块上，两者处理有出入)可以基本上确定一致，证明两种方法都可以从异常的ASM中获取数据文件

三.总结与比较
1.AMDU完全免费，aulasm超过16块硬盘需要收费
2.AMDU操作相对于aulasm麻烦一点，但是整体还是可以接受
3.获取到asm中的数据文件后恢复数据内容或者open库，那都是容易的事情
如果因为磁盘头损坏太多或者其他原因,以上方法都不能实现抽取asm磁盘组中数据文件,参考:asm disk header 彻底损坏恢复

expdp中PARALLEL和DUMPFILE关系

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今天有朋友在说PARALLEL设置为n(大于1)，DUMPFILE为一个文件(不包含%U),会出现什么样的情况。下面通过实验来说明这个问题
1.当并发数比较大时(这里实验使用4),expdp会报ORA-39095错误

[oracle@node1 tmp]$ expdp chf/xifenfei DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=4

Export: Release 11.2.0.3.0 - Production on Wed Mar 7 20:48:52 2012

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options
Starting "CHF"."SYS_EXPORT_TABLE_01":  chf/******** DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=4 
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 5.362 GB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX
ORA-39095: Dump file space has been exhausted: Unable to allocate 8192 bytes

2.并发数较少时(实验为2),通过attach观察
2.1)执行expdp导出

[oracle@node1 tmp]$ expdp chf/xifenfei DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=2

Export: Release 11.2.0.3.0 - Production on Wed Mar 7 20:49:15 2012

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options
Starting "CHF"."SYS_EXPORT_TABLE_02":  chf/******** DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=2 
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 5.362 GB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX
. . exported "CHF"."T1"                                  4.647 GB 51080958 rows
Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS
Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
Master table "CHF"."SYS_EXPORT_TABLE_02" successfully loaded/unloaded
******************************************************************************
Dump file set for CHF.SYS_EXPORT_TABLE_02 is:
  /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
Job "CHF"."SYS_EXPORT_TABLE_02" successfully completed at 20:52:23

2.2)在导出过程中，使用attach观察expdp工作情况

[oracle@node1 trace]$ expdp chf/xifenfei attach=SYS_EXPORT_TABLE_02

Export: Release 11.2.0.3.0 - Production on Wed Mar 7 20:49:38 2012

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options

Job: SYS_EXPORT_TABLE_02
  Owner: CHF                            
  Operation: EXPORT                         
  Creator Privs: TRUE                           
  GUID: BAA7964815021C96E0438C09A8C04319
  Start Time: Wednesday, 07 March, 2012 20:49:16
  Mode: TABLE                          
  Instance: chf
  Max Parallelism: 2
  EXPORT Job Parameters:
  Parameter Name      Parameter Value:
     CLIENT_COMMAND        chf/******** DUMPFILE=xifenfei.dmp TABLES=t1 PARALLEL=2 
  State: EXECUTING                      
  Bytes Processed: 0
  Current Parallelism: 2
  Job Error Count: 0
  Dump File: /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
    bytes written: 4,096
  
Worker 1 Status:
  Process Name: DW00
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE
  Completed Objects: 1
  Total Objects: 1
  Worker Parallelism: 1
  
Worker 2 Status:
  Process Name: DW02
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE_DATA
  Completed Objects: 1
  Total Objects: 1
  Completed Rows: 16,104,279
  Worker Parallelism: 1

Export> status

Job: SYS_EXPORT_TABLE_02
  Operation: EXPORT                         
  Mode: TABLE                          
  State: EXECUTING                      
  Bytes Processed: 0
  Current Parallelism: 2
  Job Error Count: 0
  Dump File: /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
    bytes written: 4,096
  
Worker 1 Status:
  Process Name: DW00
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE
  Completed Objects: 1
  Total Objects: 1
  Worker Parallelism: 1
  
Worker 2 Status:
  Process Name: DW02
  State: EXECUTING                      
  Object Schema: CHF
  Object Name: T1
  Object Type: TABLE_EXPORT/TABLE/TABLE_DATA
  Completed Objects: 1
  Total Objects: 1
  Completed Rows: 35,425,534
  Worker Parallelism: 1

Export> status

Job: SYS_EXPORT_TABLE_02
  Operation: EXPORT                         
  Mode: TABLE                          
  State: COMPLETING                     
  Bytes Processed: 4,989,989,105
  Percent Done: 100
  Current Parallelism: 2
  Job Error Count: 0
  Dump File: /opt/oracle/diag/rdbms/chf/chf/trace/xifenfei.dmp
    bytes written: 4,990,009,344
  
Worker 1 Status:
  Process Name: DW00
  State: WORK WAITING                   
  
Worker 2 Status:
  Process Name: DW02
  State: WORK WAITING

3.最终结论
3.1)如果并发设置过大，在导出过程中直接报错
3.2)如果导出文件数量少于并发数时，多于并发将不会工作。

通过sql查询rman备份信息

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查看所有备份集

    SELECT A.RECID "BACKUP SET",
         A.SET_STAMP,
         DECODE (B.INCREMENTAL_LEVEL,
                 '', DECODE (BACKUP_TYPE, 'L', 'Archivelog', 'Full'),
                 1, 'Incr-1级',
                 0, 'Incr-0级',
                 B.INCREMENTAL_LEVEL)
            "Type LV",
         B.CONTROLFILE_INCLUDED "包含CTL",
         DECODE (A.STATUS,
                 'A', 'AVAILABLE',
                 'D', 'DELETED',
                 'X', 'EXPIRED',
                 'ERROR')
            "STATUS",
         A.DEVICE_TYPE "Device Type",
         A.START_TIME "Start Time",
         A.COMPLETION_TIME "Completion Time",
         A.ELAPSED_SECONDS "Elapsed Seconds",
         --a.BYTES/1024/1024/1024 "大小(G)",
         --a.COMPRESSED,
         A.TAG "Tag",
         A.HANDLE "Path"
    FROM GV$BACKUP_PIECE A, GV$BACKUP_SET B
   WHERE A.SET_STAMP = B.SET_STAMP AND A.DELETED = 'NO'
ORDER BY A.COMPLETION_TIME DESC;

查找某个备份集中包含数据文件

SELECT distinct c.file#,A.SET_STAMP, D.NAME, C.CHECKPOINT_CHANGE#, C.CHECKPOINT_TIME
  FROM V$BACKUP_DATAFILE C, V$BACKUP_PIECE A, V$DATAFILE D
 WHERE A.SET_STAMP = C.SET_STAMP
AND D.FILE# = C.FILE#
AND A.DELETED='NO'
AND c.set_stamp=&set_stamp
ORDER BY C.FILE#;

查询某个备份集中控制文件

SELECT DISTINCT A.SET_STAMP,
                D.NAME,
                C.CHECKPOINT_CHANGE#,
                C.CHECKPOINT_TIME
  FROM V$BACKUP_DATAFILE C, V$BACKUP_PIECE A, V$CONTROLFILE D
 WHERE A.SET_STAMP = C.SET_STAMP
   AND C.FILE# = 0
   AND A.DELETED = 'NO'
   AND C.SET_STAMP = &SET_STAMP;

查看某个备份集中归档日志

SELECT DISTINCT B.SET_STAMP,
                B.THREAD#,
                B.SEQUENCE#,
                B.FIRST_TIME,
                B.FIRST_CHANGE#,
                B.NEXT_TIME,
                B.NEXT_CHANGE#
  FROM V$BACKUP_REDOLOG B, V$BACKUP_PIECE A
 WHERE A.SET_STAMP = B.SET_STAMP
   AND A.DELETED = 'NO'
   AND B.SET_STAMP = &SET_STAMP
 ORDER BY THREAD#, SEQUENCE#;

查看某个备份集SPFILE

SELECT DISTINCT A.SET_STAMP, B.COMPLETION_TIME, HANDLE
  FROM V$BACKUP_SPFILE B, V$BACKUP_PIECE A
 WHERE A.SET_STAMP = B.SET_STAMP
   AND A.DELETED = 'NO'
   AND B.SET_STAMP = &SET_STAMP;

rman配置信息

SELECT NAME,VALUE FROM V$RMAN_CONFIGURATION;

找出11g undo 回滚段名称

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当数据库启动的时报undo相关异常，很多情况下我们不得不使用隐含参数来处理(_offline_rollback_segments和_corrupted_rollback_segments)，而这个就需要明确异常的undo回滚段名称。在11g中，undo回滚段的名称发生了改变，在11g之前的版本中，回滚段名称是”_SYSTEMn$”之类，而到了11g回滚段的名称变为了”_SYSTEMn_时间戳$”，因为时间戳我们不知道，所以我们不能通过n的值，来确定回滚段的名称，从而也就不能很明确的使用_offline_rollback_segments和_corrupted_rollback_segments来标明异常回滚段。既然回滚段的名称我们可以通过dba_rollback_segs视图来查询，那么我们可以根据这个视图找到对应的回滚段是存储在哪张基表中，下面为dba_rollback_segs视图对应的sql语句

select un.name, decode(un.user#,1,'PUBLIC','SYS'),
       ts.name, un.us#, f.file#, un.block#,
       s.iniexts * ts.blocksize,
       decode(bitand(ts.flags, 3), 1, to_number(NULL),
                                      s.extsize * ts.blocksize),
       s.minexts, s.maxexts,
       decode(bitand(ts.flags, 3), 1, to_number(NULL),
                                      s.extpct),
       decode(un.status$, 2, 'OFFLINE', 3, 'ONLINE',
                          4, 'UNDEFINED', 5, 'NEEDS RECOVERY',
                          6, 'PARTLY AVAILABLE', 'UNDEFINED'),
       decode(un.inst#, 0, NULL, un.inst#), un.file#
from sys.undo$ un, sys.seg$ s, sys.ts$ ts, sys.file$ f
where un.status$ != 1
  and un.ts# = s.ts#
  and un.file# = s.file#
  and un.block# = s.block#
  and s.type# in (1, 10)
  and s.ts# = ts.ts#
  and un.ts# = f.ts#
  and un.file# = f.relfile#

通过观察，我们知道回滚段信息是存储在sys.undo$中(name字段表示回滚段名称，status$字段表示回滚段状态[1:DELETE,2:OFFLINE,3:ONLINE,4:UNDEFINED,5:NEEDS RECOVERY,6:PARTLY AVAILABLE,其他表示:UNDEFINED]),通过这个视图我们需要找的到status$为5所对应name。
找这些值较简易的方法就是通过odu抽取sys.undo$表中数据，然后在其他库上还原，然后通过sql语句查询
1.设置odu参数(config.txt)
output_format dmp,其他参数根据你的实际情况设置

2.填写system表空间对应的数据文件(control.txt)

[oracle@localhost odu]$ more control.txt 
#ts #fno   #rfno     filename                                          block_size
1     1      1       /u01/oradata/first/system01.dbf

3.odu导出数据

ODU> unload table sys.undo$

Unloading table: UNDO$,object ID: 15
Unloading segment,storage(Obj#=15 DataObj#=15 TS#=0 File#=1 Block#=224 Cluster=0)
21 rows unloaded

4.导入至新库

imp chf/xifenfei file=C:\Users\XIFENFEI\Downloads\SYS_UNDO$.dmp FROMUSER=SYS TOUSER=CHF

5.查询需要处理的回滚段

--数据库版本10g及其以上版本
set pagesize 0 feedback off verify off heading off echo off linesize 1000
select WMSYS.WM_CONCAT(name) from UNDO$ where status$=5;

--数据库版本9i及其以下版本(自己拼接)
set pagesize 0 feedback off verify off heading off echo off 
select name from UNDO$ where status$=5;

现在已经找出来了需要处理的回滚段，其他数据库恢复步骤与以前数据库相同。