达梦数据库redo log损坏处理

一.数据库服务启动中，误删redolog日志

2.逻辑导出全部数据
./dexp USERID=SYSDBA/SYSDBA FILE=FULL_DB.dmp FULL=Y DIRECTORY=…

3.初始化参数一样的库
初始化时的参数可查看dminit###.log文件（###为八位日期+6位流水）
./dminit PATH=/dm8/data PAGE_SIZE=32 EXTENT_SIZE=32 CASE_SENSITIVE=Y LENGTH_IN_CHAR=Y CHARSET=0 SYSDBA_PWD=dmorcl123456 DB_NAME=DM INSTANCE_NAME=DM LOG_SIZE=2048 PORT_NUM=5236

6.逻辑导入全部数据
./dimp USERID=SYSDBA/SYSDBA FILE=FULL_DB.dmp FULL=Y DIRECTORY=…

二：当开启归档且有备份时：

使用“备份+归档”还原一个新实例，不存在数据丢失的可能

三：无备份，无归档，不完全恢复
[dmdba@DMP dmdb]$ rm -rf dmdb01.log dmdb02.log
[dmdba@DMP bin]$ ./DmServicedmdb start
Starting DmServicedmdb: [ FAILED ]
file dm.key not found, use default license!
version info: develop
DM Database Server x64 V8 1-2-70-21.09.08-147080-10028-ENT startup…
Normal of FAST
Normal of DEFAULT
Normal of RECYCLE
Normal of KEEP
Normal of ROLL
Database mode = 0, oguid = 453331
/dm8/data/dmdb/dmdb01.log not exist, can not startup

1.初始化新库，参数与故障库参数一致
[dmdba@DMP bin]$ ./dminit PATH=/dm8/data PAGE_SIZE=32 EXTENT_SIZE=32 CASE_SENSITIVE=Y LENGTH_IN_CHAR=Y CHARSET=0 SYSDBA_PWD=dmorcl123456 DB_NAME=DM INSTANCE_NAME=DM LOG_SIZE=2048 PORT_NUM=5236

2.新库启动停止下
[dmdba@DMP bin]$ ./dmserver /dm8/data/DM/dm.ini
exit

3.拷贝新库的redolog到旧库redolog
[dmdba@DMP DM]$ cp DM01.log DM02.log /dm8/data/dmdb/

4.查看故障库systemdbf文件的魔数信息
[dmdba@DMP bin]$ ./dmmdf type=1 file=/dm8/data/dmdb/SYSTEM.DBF
dmmdf V8

1 db_magic=979613601
2 next_trxid=30113
3 pemnt_magic=327766355

Please input which parameter you want to change(1-3), q to quit: q

5.修改redolog魔数信息
[dmdba@DMP bin]$ ./dmmdf type=2 file=/dm8/data/dmdb/DM01.log —6和12
[dmdba@DMP bin]$ ./dmmdf type=2 file=/dm8/data/dmdb/DM02.log

6.数据库启动测试
[dmdba@DMP bin]$ ./DmServicedmdb start
Starting DmServicedmdb: [ FAILED ]
file dm.key not found, use default license!
version info: develop
DM Database Server x64 V8 1-2-70-21.09.08-147080-10028-ENT startup…
Normal of FAST
Normal of DEFAULT
Normal of RECYCLE
Normal of KEEP
Normal of ROLL
Database mode = 0, oguid = 453331
/dm8/data/dmdb/dmdb01.log not exist, can not startup

7.转存控制文件
[dmdba@DMP bin]$ ./dmctlcvt type=1 src=/dm8/data/dmdb/dm.ctl dest=/tmp/ctl.txt
DMCTLCVT V8
convert ctl to txt success!

8.修改redolog名字

file path

fil_path=/dm8/data/dmdb/DM01.log

file path

fil_path=/dm8/data/dmdb/DM02.log

9.文本文件转存控制文件
[dmdba@DMP bin]$ ./dmctlcvt type=2 src=/tmp/ctl.txt dest=/dm8/data/dmdb/dm.ctl
DMCTLCVT V8
convert txt to ctl success!

10.重新启动数据库测试
[dmdba@DMP bin]$ ./DmServicedmdb start
Starting DmServicedmdb: [ OK ]

11.不完全恢复成功，备份数据库