您可以使用 db2pd 或 LIST UTILITIES 命令来监视数据库前滚操作的进度。
过程
结果
对于前滚恢复，进度监视分为两个阶段：FORWARD 和 BACKWARD。FORWARD 阶段期间中，读取日志文件并将日志记录应用于数据库。对于前滚恢复，当此阶段开始时，将工作总量估计值指定为 UNKNOWN。按字节计的已处理工作量将随进程的继续而更新。
在 BACKWARD 阶段中，回滚 FORWARD 阶段期间中应用任何未落实的更改。提供了要处理的日志数据量的估计值（按字节计）。当进程继续运行时，会更新已处理的工作量（按字节计）。
示例
以下示例是使用 db2pd 命令监视前滚操作性能所获得的输出：
Recovery:
Recovery Status 0x00000401
Current Log S0000005.LOG
Current LSN 0000001F07BC
Current LSO 000002551BEA
Job Type ROLLFORWARD RECOVERY
Job ID 7
Job Start Time (1107380474) Wed Feb 2 16:41:14 2005
Job Description Database Rollforward Recovery
Invoker Type User
Total Phases 2
Current Phase 1
Progress:
Address PhaseNum Description StartTime CompletedWork TotalWork
0x0000000200667160 1 Forward Wed Feb 2 16:41:14 2005 2268098 bytes Unknown
0x0000000200667258 2 Backward NotStarted 0 bytes Unknown以下示例是使用附带 SHOW DETAIL 选项的 LIST UTILITIES 命令监视数据库前滚操作性能所获得的输出：
ID = 7
Type = ROLLFORWARD RECOVERY
Database Name = TESTDB
Member Number = 0
Description = Database Rollforward Recovery
Start Time = 01/11/2012 16:56:53.770404
State = Executing
Invocation Type = User
Progress Monitoring:
Estimated Percentage Complete = 50
Phase Number = 1
Description = Forward
Total Work = 928236 bytes
Completed Work = 928236 bytes
Start Time = 01/11/2012 16:56:53.770492
Phase Number [Current] = 2
Description = Backward
Total Work = 928236 bytes
Completed Work = 0 bytes
Start Time = 01/11/2012 16:56:56.886036以下示例是使用附带 SHOW DETAIL 选项的 LIST UTILITIES 命令监视表空间前滚操作性能所获得的输出：
ID = 17
Type = ROLLFORWARD RECOVERY
Database Name = TESTDB
Member Number = 0
Description = Offline Tablespace Rollforward Recovery: 3
Start Time = 01/11/2012 17:04:27.269171
State = Executing
Invocation Type = User
Progress Monitoring:
Estimated Percentage Complete = 63
Phase Number = 1
Description = Forward
Total Work = 142
Completed Work = 90
Start Time = 01/11/2012 17:04:27.269283
Phase Number [Current] = 2
Description = Backward
Total Work = 0
Completed Work = 0
Start Time = Not Started
关于crash recovery
如果DB2数据库遭受断电或者异常关闭，数据库没有干净的关闭，那么数据库在启动的时候将会
进行crash recovery. 但是如果数据库参数AUTORESTART设置为OFF的话，在启动数据库后DB2不会
进行CRASH RECOVERY。我们在连接到数据库的时候将会报SQL1015N 错误。
[yansp@db2server ~]$ db2 get db cfg for oracle | grep AUTORESTART
Auto restart enabled (AUTORESTART) = OFF
db2 => connect to oracle @
SQL1015N The database is in an inconsistent state. SQLSTATE=55025
这个时候需要我们手工进行CRASH RECOVERY。
db2 => restart database oracle @
DB20000I The RESTART DATABASE command completed successfully.
db2 => connect to oracle @
Database Connection Information
Database server = DB2/LINUX 9.7.0
SQL authorization ID = YANSP
Local database alias = ORACLE
通过日志文件我们看一下DB2 CRASH RECOVERY的过程。
2013-02-03-06.27.22.704092+480 I1529901G434 LEVEL: Warning
PID : 9899 TID : 2947541904 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-15 APPID: *LOCAL.yansp.130202222719
AUTHID : YANSP
EDUID : 35 EDUNAME: db2agent (ORACLE) 0
FUNCTION: DB2 UDB, base sys utilities, sqledint, probe:30
MESSAGE : Crash Recovery is needed. <-- 需要进行crash recovery
2013-02-03-06.27.31.389376+480 I1530336G497 LEVEL: Warning
PID : 9899 TID : 2947541904 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-15 APPID: *LOCAL.yansp.130202222719
AUTHID : YANSP
EDUID : 35 EDUNAME: db2agent (ORACLE) 0
FUNCTION: DB2 UDB, recovery manager, sqlpresr, probe:410
MESSAGE : Crash recovery started. LowtranLSN 00000000252E0010 MinbuffLSN <--启动 Crash recovery
00000000252E0010
2013-02-03-06.27.31.463994+480 E1530834G451 LEVEL: Warning
PID : 9899 TID : 2947541904 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-15 APPID: *LOCAL.yansp.130202222719
AUTHID : YANSP
EDUID : 35 EDUNAME: db2agent (ORACLE) 0
FUNCTION: DB2 UDB, recovery manager, sqlpresr, probe:410
MESSAGE : ADM1530E Crash recovery has been initiated. <-初始化 Crash recovery
2013-02-03-06.27.31.643060+480 I1531286G492 LEVEL: Warning
PID : 9899 TID : 2947541904 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-15 APPID: *LOCAL.yansp.130202222719
AUTHID : YANSP
EDUID : 35 EDUNAME: db2agent (ORACLE) 0
FUNCTION: DB2 UDB, recovery manager, sqlprecm, probe:2000
DATA #1 : <preformatted>
Using parallel recovery with 3 agents 8 QSets 24 queues and 16 chunks <- 启动并行进程来进行Crash recovery
2013-02-03-06.27.31.933175+480 I1531779G351 LEVEL: Warning
PID : 9899 TID : 2945444752 PROC : db2sysc 0
INSTANCE: yansp NODE : 000
EDUID : 40 EDUNAME: db2lfr (ORACLE) 0
FUNCTION: DB2 UDB, data protection services, sqlpgarl, probe:99
MESSAGE : INFO ONLY: Found an old page in the log file <-DB2发现日志文件中有OLD PAGE
2013-02-03-06.27.32.700437+480 I1532131G507 LEVEL: Warning
PID : 9899 TID : 2947541904 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-15 APPID: *LOCAL.yansp.130202222719
AUTHID : YANSP
EDUID : 35 EDUNAME: db2agent (ORACLE) 0
FUNCTION: DB2 UDB, recovery manager, sqlprecm, probe:4000
MESSAGE : DIA2051W Forward phase of crash recovery has completed. Next LSN is <--前滚恢复完成
"00000000252E7400".
2013-02-03-06.27.33.293191+480 E1532639G460 LEVEL: Warning
PID : 9899 TID : 2947541904 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-15 APPID: *LOCAL.yansp.130202222719
AUTHID : YANSP
EDUID : 35 EDUNAME: db2agent (ORACLE) 0
FUNCTION: DB2 UDB, recovery manager, sqlpresr, probe:3170
MESSAGE : ADM1531E Crash recovery has completed successfully. <--CRASH RECOVERY成功完成
2013-02-03-06.27.33.294698+480 I1533100G462 LEVEL: Warning
PID : 9899 TID : 2947541904 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-15 APPID: *LOCAL.yansp.130202222719
AUTHID : YANSP
EDUID : 35 EDUNAME: db2agent (ORACLE) 0
FUNCTION: DB2 UDB, recovery manager, sqlpresr, probe:3170
MESSAGE : Crash recovery completed. Next LSN is 00000000252E7400
2013-02-03-06.27.34.627484+480 E1533563G464 LEVEL: Event
PID : 9899 TID : 2949639056 PROC : db2sysc 0
INSTANCE: yansp NODE : 000 DB : ORACLE
APPHDL : 0-16 APPID: *LOCAL.DB2.130202222734
AUTHID : YANSP
EDUID : 34 EDUNAME: db2stmm (ORACLE) 0
FUNCTION: DB2 UDB, Self tuning memory manager, stmmLog, probe:1008
DATA #1 : <preformatted>
Starting STMM log from file number 0
整个恢复过程都是有主控进程PID=9899 DB2SYSC进程来完成的。
[yansp@db2server ~]$ ps -ef | grep 9899
yansp 9899 9897 0 06:16 pts/0 00:00:06 db2sysc 0
root 9900 9899 0 06:16 pts/0 00:00:00 db2ckpwd 0
root 9901 9899 0 06:16 pts/0 00:00:00 db2ckpwd 0
root 9902 9899 0 06:16 pts/0 00:00:00 db2ckpwd 0
yansp 12571 11322 1 06:33 pts/2 00:00:00 grep 9899