客户环境是运行在xx厂商上的云环境的Oracle RAC,由于其中一块asm disk资源到期没有进行续费,云厂商对该盘进行了限速(1MB/s,并且异步写入),导致运行在该rac上的数据库直接crash,客户续费之后磁盘速度恢复正常但是数据库启动报ORA-00353 ORA-00312错误(redo异常),客户找了以前的服务商进行恢复尝试没有成功.对接手后的现场进行检测,发现有20个数据文件被初始化(dbv检测全部是空块,没有写入任何表和索引数据)[直接变成了空文件,一般sqlplus中执行alter database create datafile或者在没有对应的数据文件备份的情况下执行restore datafile会出现这个情况],数据库被强制拉库,但是启动没有成功报ORA-00704 ORA-01555错误.由于客户明天领导会过来检查,所以着急启动系统,我们只能基于现在的现况给客户强制拉起来库,赌运气看看核心业务是否可以跑起来

回溯处理过程,续费欠费资源之后,数据库启动报错(估计是当时限速之后,云存储层面异步写入导致部分写丢失)

Mon Oct 26 11:38:19 2026
alter database open
This instance was first to open
Beginning crash recovery of 1 threads
 parallel recovery started with 15 processes
Started redo scan
Incomplete read from log member '+DATA/xff/onlinelog/group_3.312.1210628353'. Trying next member.
Incomplete read from log member '+DATA/xff/onlinelog/group_3.312.1210628353'. Trying next member.
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_ora_19144.trc  (incident=682004):
ORA-00353: log corruption near block 47146 change 16921129940671 time 10/26/2026 08:57:37
ORA-00312: online log 3 thread 1: '+DATA/xff/onlinelog/group_3.312.1210628353'
Incident details in: /oracle/diag/rdbms/xff/xff1/incident/incdir_682004/xff1_ora_19144_i682004.trc
Abort recovery for domain 0
Aborting crash recovery due to error 368
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_ora_19144.trc:
ORA-00368: checksum error in redo log block
ORA-00353: log corruption near block 47146 change 16921129940671 time 10/26/2026 08:57:37
ORA-00312: online log 3 thread 1: '+DATA/xff/onlinelog/group_3.312.1210628353'
Abort recovery for domain 0
Mon Oct 26 11:38:22 2026
Sweep [inc][682004]: completed
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_ora_19144.trc:
ORA-00368: checksum error in redo log block
ORA-00353: log corruption near block 47146 change 16921129940671 time 10/26/2026 08:57:37
ORA-00312: online log 3 thread 1: '+DATA/xff/onlinelog/group_3.312.1210628353'
ORA-368 signalled during: alter database open...

屏蔽一致性,强制resetlogs的时候报ORA-00704 ORA-01555错误

Mon Oct 26 15:47:43 2026
Setting recovery target incarnation to 2
Initializing SCN for created control file
Database SCN compatibility initialized to 3
Warning - High Database SCN: Current SCN value is 16917769616373, threshold SCN value is 0
Mon Oct 26 15:47:43 2026
Assigning activation ID 2556751686 (0x9864ef46)
LGWR: STARTING ARCH PROCESSES
Mon Oct 26 15:47:43 2026
ARC0 started with pid=32, OS id=14392 
ARC0: Archival started
LGWR: STARTING ARCH PROCESSES COMPLETE
ARC0: STARTING ARCH PROCESSES
Mon Oct 26 15:47:44 2026
ARC1 started with pid=33, OS id=14446 
Mon Oct 26 15:47:44 2026
ARC2 started with pid=34, OS id=14448 
Mon Oct 26 15:47:44 2026
ARC3 started with pid=35, OS id=14450 
ARC1: Archival started
ARC2: Archival started
ARC1: Becoming the 'no FAL' ARCH
ARC1: Becoming the 'no SRL' ARCH
ARC2: Becoming the heartbeat ARCH
Thread 1 opened at log sequence 1
  Current log# 1 seq# 1 mem# 0: +DATA/xff/onlinelog/group_1.314.1210628351
Successful open of redo thread 1
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Mon Oct 26 15:47:44 2026
SMON: enabling cache recovery
ORA-01555 caused by SQL statement below (SQL ID: 7bd391hat42zk, SCN: 0x0f62.f9a5fbf8):
select /*+ rule */ name,file#,block#,status$,user#,undosqn,xactsqn,scnbas,scnwrp,
DECODE(inst#,0,NULL,inst#),ts#,spare1 from undo$ where us#=:1
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_ora_13439.trc:
ORA-00704: bootstrap process failure
ORA-00704: bootstrap process failure
ORA-00604: error occurred at recursive SQL level 2
ORA-01555: snapshot too old: rollback segment number 0 with name "SYSTEM" too small
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_ora_13439.trc:
ORA-00704: bootstrap process failure
ORA-00704: bootstrap process failure
ORA-00604: error occurred at recursive SQL level 2
ORA-01555: snapshot too old: rollback segment number 0 with name "SYSTEM" too small
Error 704 happened during db open, shutting down database
USER (ospid: 13439): terminating the instance due to error 704
Instance terminated by USER, pid = 13439
ORA-1092 signalled during: ALTER DATABASE OPEN RESETLOGS...
opiodr aborting process unknown ospid (13439) as a result of ORA-1092

从这个时候开始我接手这个故障,数据完全恢复已经不太可能,只能基于现在的情况,给客户尝试拉起来库,看看核心业务是否可以跑起来.
数据库open过程报ORA-01555错误,这个是一个比较常见的问题,以前专门写过类似文章:
在数据库open过程中常遇到ORA-01555汇总
数据库open过程遭遇ORA-1555对应sql语句补充
对于这个客户问题,我也一样尝试修改scn的方式来解决

SQL> set numw 16
col CHECKPOINT_TIME for a40
set lines 150
set pages 1000
SELECT status,
to_char(checkpoint_time,'yyyy-mm-dd hh24:mi:ss') checkpoint_time,FUZZY,checkpoint_change#,
count(*) ROW_NUM
FROM v$datafile_header
GROUP BY status, checkpoint_change#, to_char(checkpoint_time,'yyyy-mm-dd hh24:mi:ss'),fuzzy
ORDER BY status, checkpoint_change#, checkpoint_time;SQL> SQL> SQL> SQL>   2    3    4    5    6  

STATUS  CHECKPOINT_TIME                          FUZ CHECKPOINT_CHANGE#          ROW_NUM
------- ---------------------------------------- --- ------------------ ----------------
ONLINE  2026-10-26 15:47:44                      YES     16917769616374              191

使用obet的patch_scn功能来修改数据库scn（obet的patch_scn功能）

OBET> patch_scn 89103 0x06001AE70 0xF62FBA5FBF6
 
=== Oracle SCN Patch ===
PID:     89103
Address: 0x06001AE70
New Value: 0xF62FBA5FBF6 (16917803170806)
Original SCN: 0x0
 
Are you sure you want to modify Oracle SCN? (yes/no): y
 
SCN modified: 0x0 -> 0xF62FBA5FBF6
Oracle SCN successfully modified.


SQL> oradebug DUMPvar SGA kcsgscn_ 
kcslf kcsgscn_ [06001AE70, 06001AEA0) = FBA5FBF6 00000F62 00000000 00000000 00000000

然后尝试打开数据库依旧报ORA-01555错误,证明我们处理的scn不正确

SQL> recover database using backup controlfile;
ORA-00279: change 16917769616374 generated at 10/26/2026 15:47:44 needed for
thread 1
ORA-00289: suggestion : +ARCH
ORA-00280: change 16917769616374 for thread 1 is in sequence #1


Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
+DATA/xff/onlinelog/group_1.314.1210628351
Log applied.
Media recovery complete.
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-00704: bootstrap process failure
ORA-00704: bootstrap process failure
ORA-00604: error occurred at recursive SQL level 2
ORA-01555: snapshot too old: rollback segment number 0 with name "SYSTEM" too small
Process ID: 18169
Session ID: 3681 Serial number: 2825

分析异常block的scn

*** 2026-10-27 01:05:42.156
Start dump data block from file +DATA/xff/system01.dbf minblk 558 maxblk 558
 V10 STYLE FILE HEADER:
        Compatibility Vsn = 186647552=0xb200400
        Db ID=2195614447=0x82de6aef, Db Name='xff'
        Activation ID=0=0x0
        Control Seq=542=0x21e, File size=446720=0x6d100
        File Number=1, Blksiz=8192, File Type=3 DATA
Dump all the blocks in range:
buffer tsn: 0 rdba: 0x0040022e (1/558)
scn: 0x0f63.c1efd2ab seq: 0x01 flg: 0x04 tail: 0xd2ab0201
frmt: 0x02 chkval: 0x75a3 type: 0x02=KTU UNDO BLOCK
Hex dump of block: st=0, typ_found=1

发现该block的scn非常大0x0f63.c1efd2ab,我之前处理的scn明显不合适,继续换上新的scn,再次打开数据库成功

OBET> patch_scn 89103 0x06001AE70 0xF64C1EFD2AB
 
=== Oracle SCN Patch ===
PID:     89103
Address: 0x06001AE70
New Value: 0xF64C1EFD2AB(16925424865963)
Original SCN: 0x0
 
Are you sure you want to modify Oracle SCN? (yes/no): y
 
SCN modified: 0x0 -> 0xF64C1EFD2AB
Oracle SCN successfully modified.


SQL> oradebug DUMPvar SGA kcsgscn_ 
kcslf kcsgscn_ [06001AE70, 06001AEA0) = C1EFD2AB 00000F64 00000000 00000000 00000000
SQL> 

SQL> 
SQL> 
SQL> alter database open;

Database altered.
[/sql]
后续大量异常undo问题
1
ORA-00376: file 182 cannot be read at this time
ORA-01111: name for data file 182 is unknown - rename to correct file
ORA-01110: data file 182: '/oracle/product/11.2.0/db_1/dbs/MISSING00182'
ORACLE Instance xff1 (pid = 20) - Error 1578 encountered while recovering transaction (21, 29) on object 99404.
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_smon_29435.trc:
ORA-01578: ORACLE data block corrupted (file # 8, block # 1471227)
ORA-01110: data file 8: '+DATA/xff/users04.dbf'
ORACLE Instance xff1 (pid = 20) - Error 376 encountered while recovering transaction (2, 27) on object 599926.
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_smon_29435.trc:
ORA-00376: file 211 cannot be read at this time
ORA-01111: name for data file 211 is unknown - rename to correct file
ORA-01110: data file 211: '/oracle/product/11.2.0/db_1/dbs/MISSING00211'
ORACLE Instance xff1 (pid = 20) - Error 376 encountered while recovering transaction (10, 6) on object 99591.
Errors in file /oracle/diag/rdbms/xff/xff1/trace/xff1_smon_29435.trc:
ORA-00376: file 182 cannot be read at this time
ORA-01111: name for data file 182 is unknown - rename to correct file
ORA-01110: data file 182: '/oracle/product/11.2.0/db_1/dbs/MISSING0018

由于这些文件已经被初始化掉了,恢复已经没有意义,直接没有加入到ctl中,现在主要是由于有些事务涉及这些文件,导致smon回滚的时候报这些错误,对于这样的异常,直接对于undo进行重建更换新undo即可.处理好这些问题之后,数据库open运行问题,客户自行安排业务测试和论证