ASM磁盘分区或者设备文件删除后恢复的方法

赵宇 · 发表于 2008-7-15 14:04

$ export ORACLE_SID=+ASM
$ sqlplus / as sysdba

查看磁盘组的状态和磁盘组的类型,这里的磁盘组是外部
SQL> select name,type,state from v$asm_diskgroup;

NAME                TYPE       STATE
-------------------- ------------ ----------------------
DISK_GROUP1       EXTERN    MOUNTED
DISK_GROUP2       EXTERN    MOUNTED
FLASHBACK_DISKGROUP  EXTERN    MOUNTED

查看磁盘组对应的磁盘,为什么会ORCL:VOL这些磁盘没有分配,实际这些磁盘就是
ASM磁盘,由于他们有标识设备文件,所以没有对应磁盘组,如果它们没有标识设备,会对应
磁盘,我们看一下:
SQL> select group_number,disk_number,path from v$asm_disk;

GROUP_NUMBER DISK_NUMBER PATH
------------ ----------- --------------------
         0          3 ORCL:VOL1
         0          5 ORCL:VOL3
         0          6 ORCL:VOL4
         2          0 /dev/raw/raw3
         3          0 /dev/raw/raw2
         1          1 /dev/raw/raw4
         1          0 ORCL:VOL2

7 rows selected.

$ /etc/init.d/oracleasm listdisks
VOL1
VOL2
VOL3
VOL4

发现其他的ASMDISK的设备文件都直接对应了磁盘组,但是VOL2却直接对应磁盘组.
看到VOL2没有定义标识,我们来定义一下.
$ /etc/init.d/oracleasm querydisk VOL1
Disk "VOL1" is a valid ASM disk on device [8, 17]
$ /etc/init.d/oracleasm querydisk VOL2
ASM disk "VOL2" defines an unmarked device
$ /etc/init.d/oracleasm querydisk VOL3
Disk "VOL3" is a valid ASM disk on device [8, 49]
$ /etc/init.d/oracleasm querydisk VOL4
Disk "VOL4" is a valid ASM disk on device [8, 81]

$ su - root
Password:
-bash: [: missing `]'
[root@dg1 ~]# vi /etc/sysconfig/rawdevices
加入 /dev/raw/raw1 /dev/sdc1这条

[root@dg1 ~]# /sbin/service rawdevices restart
Assigning devices:
         /dev/raw/raw3  --> /dev/sdb1
/dev/raw/raw3:  bound to major 8, minor 17
         /dev/raw/raw2  --> /dev/sdd1
/dev/raw/raw2:  bound to major 8, minor 49
         /dev/raw/raw4  --> /dev/sdf1
/dev/raw/raw4:  bound to major 8, minor 81
         /dev/raw/raw1  --> /dev/sdc1
/dev/raw/raw1:  bound to major 8, minor 33
done

[root@dg1 ~]# cd /dev/raw
[root@dg1 raw]# ls
raw1  raw2  raw3  raw4

RAW1文件已经生成,在到V$ASM_DISK表看一下
  1* select group_number,name,path,state from v$asm_disk
SQL> /

GROUP_NUMBER NAME                   PATH                STATE
------------ ------------------------- -------------------- ----------------
         0                         ORCL:VOL1          NORMAL
         0                         ORCL:VOL2          NORMAL
         0                         ORCL:VOL3          NORMAL
         0                         ORCL:VOL4          NORMAL
         2 DISK_GROUP2_0000       /dev/raw/raw3       NORMAL
         3 FLASHBACK_DISKGROUP_0000  /dev/raw/raw2       NORMAL
         1 DISK_GROUP1_0001       /dev/raw/raw4       NORMAL
         1 DISK_GROUP1_0000       /dev/raw/raw1       NORMAL

8 rows selected.
发现VOL2已经不对应磁盘组了.

赵宇 · 发表于 2008-7-15 14:08

模拟删除ASMDISK以及磁盘分区的过程:

首先删除了ASMDISK,并没有实际删除磁盘分区
$ su - root
Password:
-bash: [: missing `]'
[root@dg1 ~]# /etc/init.d/oracleasm deletedisk VOL2
Removing ASM disk "VOL2":                               [  OK  ]

SQL> startup nomount
ASM instance started

Total System Global Area 83886080 bytes
Fixed Size                1217836 bytes
Variable Size             57502420 bytes
ASM Cache                25165824 bytes

SQL> alter diskgroup DISK_GROUP1 mount;
alter diskgroup DISK_GROUP1 mount
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15063: ASM discovered an insufficient number of disks for diskgroup
"DISK_GROUP1"

再重新创建ASMDISK:
$ su - root
Password:
-bash: [: missing `]'
[root@dg1 ~]# /etc/init.d/oracleasm createdisk VOL2 /dev/sdc1
Marking disk "/dev/sdc1" as an ASM disk:                [  OK  ]
[root@dg1 ~]# /etc/init.d/oracleasm listdisks
VOL1
VOL2
VOL3
VOL4

发现磁盘组已经不能正常mount:

SQL> alter diskgroup DISK_GROUP1 mount;
alter diskgroup DISK_GROUP1 mount
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15063: ASM discovered an insufficient number of disks for diskgroup
"DISK_GROUP1"

用以前ASM磁盘头的备份信息进行恢复:
SQL> !
$ dd if=/u01/asmdisk_header/raw1_header bs=4096 count=1 of=/dev/raw/raw1
读入了 1+0 个块
输出了 1+0 个块
$ exit

SQL> l
  1* alter diskgroup DISK_GROUP1 mount
SQL> /
Diskgroup altered.

赵宇 · 发表于 2008-7-15 14:12

现在删除磁盘分区,再测试:
[root@dg1 ~]# fdisk /dev/sdc

Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)

Command (m for help): p

Disk /dev/sdc: 1610 MB, 1610612736 bytes
255 heads, 63 sectors/track, 195 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot    Start       End    Blocks Id  System
/dev/sdc1             1       195    1566306 83  Linux
磁盘只划了1个分区

Command (m for help): d
Selected partition 1

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Command (m for help): p
Disk /dev/sdc: 1610 MB, 1610612736 bytes
255 heads, 63 sectors/track, 195 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot    Start       End    Blocks Id  System
/dev/sdc1             1       195    1566306 83  Linux

实际删除分区
Command (m for help): d
Selected partition 1

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Command (m for help): p

Disk /dev/sdc: 1610 MB, 1610612736 bytes
255 heads, 63 sectors/track, 195 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot    Start       End    Blocks Id  System

分区已经被删除.

SQL> alter diskgroup DISK_GROUP1 mount;
alter diskgroup DISK_GROUP1 mount
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15063: ASM discovered an insufficient number of disks for diskgroup
"DISK_GROUP1"

SQL> !
$ dd if=/u01/asmdisk_header/raw1_header bs=4096 count=1 of=/dev/raw/raw1
dd: 打开 ‘/dev/raw/raw1’: 没有那个设备或地址
$ cd /dev/raw
$ ls
raw1  raw2  raw3  raw4
$ ls -l
总用量 0
crw-rw----  1 oracle dba 162, 1  7月 15 11:24 raw1
crw-rw----  1 oracle dba 162, 2  7月 15 11:24 raw2
crw-rw----  1 oracle dba 162, 3  7月 15 11:24 raw3
crw-rw----  1 oracle dba 162, 4  7月 15 11:24 raw4

其实设备文件还在,但是已经不能对应到磁盘分区.因为分区已经删除,这个磁盘组肯定不能mount
尝试重建分区:
[root@dg1 ~]# fdisk /dev/sdc

Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)

Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-195, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-195, default 195):
Using default value 195

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

oradbHome · 发表于 2008-7-15 14:19

用以前ASM磁盘头的备份信息进行恢复:
SQL> !
$ dd if=/u01/asmdisk_header/raw1_header bs=4096 count=1 of=/dev/raw/raw1
读入了 1+0 个块
输出了 1+0 个块
$ exit

问下 asm diskgroup 的配置信息就在raw的第一个block上吗?

赵宇 · 发表于 2008-7-15 14:20

用备份还原磁盘头信息:
$ dd if=/u01/asmdisk_header/raw1_header bs=4096 count=1 of=/dev/raw/raw1
读入了 1+0 个块
输出了 1+0 个块
$ env |grep ORA
ORACLE_BASE=/u01/app/oracle
ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1
ORACLE_SID=+ASM
$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Tue Jul 15 13:40:41 2008

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

Connected to an idle instance.

SQL> startup nomount
ASM instance started

Total System Global Area 83886080 bytes
Fixed Size                1217836 bytes
Variable Size             57502420 bytes
ASM Cache                25165824 bytes
SQL>

SQL> alter diskgroup DISK_GROUP1 mount;

Diskgroup altered.

$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Tue Jul 15 13:41:28 2008

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

Connected to an idle instance.

SQL> startup mount
ORACLE instance started.

Total System Global Area  197132288 bytes
Fixed Size                1218484 bytes
Variable Size             83888204 bytes
Database Buffers       109051904 bytes
Redo Buffers             2973696 bytes
ORA-00205: error in identifying control file, check alert log for more info

ALTER DATABASE MOUNT
Tue Jul 15 13:41:35 2008
Starting background process ASMB
ASMB started with pid=16, OS id=3352
Starting background process RBAL
RBAL started with pid=17, OS id=3356
Tue Jul 15 13:41:40 2008
SUCCESS: diskgroup DISK_GROUP1 was mounted
Tue Jul 15 13:41:40 2008
ORA-00202: ????: ''+FLASHBACK_DISKGROUP/devdb/controlfile/current.256.657732291''
ORA-17503: ksfdopn: 2 ?????? +FLASHBACK_DISKGROUP/devdb/controlfile/current.256.657732291
ORA-15001: ??? "FLASHBACK_DISKGROUP" ????????
ORA-15001: diskgroup "FLASHBACK_DISKGROUP" does not exist or is not mounted
SUCCESS: diskgroup DISK_GROUP1 was dismounted
Tue Jul 15 13:41:40 2008
ORA-205 signalled during: ALTER DATABASE MOUNT...

因为其他磁盘组没有装载,导致controlfile不能全部找到,回到ASM instance mount所有磁盘组

$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Tue Jul 15 13:43:21 2008

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

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> alter diskgroup DISK_GROUP1 dismount;

Diskgroup altered.

SQL> alter diskgroup all mount;

Diskgroup altered.

QL> startup mount
ORACLE instance started.

Total System Global Area  197132288 bytes
Fixed Size                1218484 bytes
Variable Size             83888204 bytes
Database Buffers       109051904 bytes
Redo Buffers             2973696 bytes
Database mounted.

SQL> alter database open;

Database altered.

SQL> select file_name from dba_data_files;

FILE_NAME
----------------------------------------------------------------------------------------------------
+DISK_GROUP1/devdb/datafile/users.259.657732133
+DISK_GROUP1/devdb/datafile/sysaux.257.657732131
+DISK_GROUP1/devdb/datafile/undotbs1.258.657732131
+DISK_GROUP1/devdb/datafile/system.256.657732131
+DISK_GROUP1/devdb/datafile/example.265.657732351
+DISK_GROUP2/devdb/datafile/users.256.659787481

6 rows selected.

发现数据库可以正常打开,数据没有丢失.

总结: 磁盘划分区以后,在Linux下通过asm lib用oracleasm命令创建ASM磁盘,然后在/etc/sysconfig/rawdevices创建设备文件

disk partition (fdisk -l查看)->asm disk (/etc/init.d/oracleasm listdisks 查看)->more /etc/sysconfig/rawdevices or ls -l
/dev/raw/raw*查看

测试看出,删除raw 设备文件,磁盘组仍然可以直接读取asm disk,但是如果磁盘分区或者asm disk被删除,需要利用备份进行恢复

请兄弟门指正测试中不足,错误的地方

owlstudio · 发表于 2008-7-15 16:42

好好试试，先顶一个！

paulyibinyi · 发表于 2008-7-15 17:10

谢谢分享 mark

jieyancai · 发表于 2008-7-15 17:19

没怎么研究asm，留个记号。

五“宅”一生 · 发表于 2008-7-15 22:17

好文章。找个时间做做实验。谢谢

赵宇 · 发表于 2008-7-16 08:25

原帖由 oradbHome 于 2008-7-15 14:19 发表
问下 asm diskgroup 的配置信息就在raw的第一个block上吗?

$ kfed read /dev/raw/raw1
kfbh.endian:                         1 ; 0x000: 0x01
kfbh.hard:                         130 ; 0x001: 0x82
kfbh.type:                         1 ; 0x002: KFBTYP_DISKHEAD
kfbh.datfmt:                         1 ; 0x003: 0x01
kfbh.block.blk:                      0 ; 0x004: T=0 NUMB=0x0
kfbh.block.obj:             2147483648 ; 0x008: TYPE=0x8 NUMB=0x0
kfbh.check:                452538402 ; 0x00c: 0x1af93022
kfbh.fcn.base:                   4532 ; 0x010: 0x000011b4
kfbh.fcn.wrap:                      0 ; 0x014: 0x00000000
kfbh.spare1:                         0 ; 0x018: 0x00000000
kfbh.spare2:                         0 ; 0x01c: 0x00000000
kfdhdb.driver.provstr:    ORCLDISKVOL2 ; 0x000: length=12
kfdhdb.driver.reserved[0]: 843861846 ; 0x008: 0x324c4f56
kfdhdb.driver.reserved[1]:          0 ; 0x00c: 0x00000000
kfdhdb.driver.reserved[2]:          0 ; 0x010: 0x00000000
kfdhdb.driver.reserved[3]:          0 ; 0x014: 0x00000000
kfdhdb.driver.reserved[4]:          0 ; 0x018: 0x00000000
kfdhdb.driver.reserved[5]:          0 ; 0x01c: 0x00000000
kfdhdb.compat:             168820736 ; 0x020: 0x0a100000
kfdhdb.dsknum:                      0 ; 0x024: 0x0000
kfdhdb.grptyp:                      1 ; 0x026: KFDGTP_EXTERNAL
kfdhdb.hdrsts:                      3 ; 0x027: KFDHDR_MEMBER
kfdhdb.dskname:       DISK_GROUP1_0000 ; 0x028: length=16
kfdhdb.grpname:          DISK_GROUP1 ; 0x048: length=11
kfdhdb.fgname:       DISK_GROUP1_0000 ; 0x068: length=16
kfdhdb.capname:                      ; 0x088: length=0
kfdhdb.crestmp.hi:          32905806 ; 0x0a8: HOUR=0xe DAYS=0x12 MNTH=0x6 YEAR=0x7d8
kfdhdb.crestmp.lo:          2565405696 ; 0x0ac: USEC=0x0 MSEC=0x23f SECS=0xe MINS=0x26
kfdhdb.mntstmp.hi:          32906736 ; 0x0b0: HOUR=0x10 DAYS=0xf MNTH=0x7 YEAR=0x7d8
kfdhdb.mntstmp.lo:          2152955904 ; 0x0b4: USEC=0x0 MSEC=0xe0 SECS=0x5 MINS=0x20
kfdhdb.secsize:                   512 ; 0x0b8: 0x0200
kfdhdb.blksize:                   4096 ; 0x0ba: 0x1000
kfdhdb.ausize:                1048576 ; 0x0bc: 0x00100000
kfdhdb.mfact:                   113792 ; 0x0c0: 0x0001bc80
kfdhdb.dsksize:                   1529 ; 0x0c4: 0x000005f9
kfdhdb.pmcnt:                      2 ; 0x0c8: 0x00000002
kfdhdb.fstlocn:                      1 ; 0x0cc: 0x00000001
kfdhdb.altlocn:                      2 ; 0x0d0: 0x00000002
kfdhdb.f1b1locn:                   2 ; 0x0d4: 0x00000002
kfdhdb.redomirrors[0]:             0 ; 0x0d8: 0x0000
kfdhdb.redomirrors[1]:          65535 ; 0x0da: 0xffff
kfdhdb.redomirrors[2]:          65535 ; 0x0dc: 0xffff
kfdhdb.redomirrors[3]:          65535 ; 0x0de: 0xffff
kfdhdb.dbcompat:             168820736 ; 0x0e0: 0x0a100000
kfdhdb.grpstmp.hi:          32905806 ; 0x0e4: HOUR=0xe DAYS=0x12 MNTH=0x6 YEAR=0x7d8
kfdhdb.grpstmp.lo:          2565314560 ; 0x0e8: USEC=0x0 MSEC=0x1e6 SECS=0xe MINS=0x26
kfdhdb.ub4spare[0]:                0 ; 0x0ec: 0x00000000
kfdhdb.ub4spare[1]:                0 ; 0x0f0: 0x00000000
kfdhdb.ub4spare[2]:                0 ; 0x0f4: 0x00000000
kfdhdb.ub4spare[3]:                0 ; 0x0f8: 0x00000000
kfdhdb.ub4spare[4]:                0 ; 0x0fc: 0x00000000
kfdhdb.ub4spare[5]:                0 ; 0x100: 0x00000000
kfdhdb.ub4spare[6]:                0 ; 0x104: 0x00000000
kfdhdb.ub4spare[7]:                0 ; 0x108: 0x00000000
kfdhdb.ub4spare[8]:                0 ; 0x10c: 0x00000000
kfdhdb.ub4spare[9]:                0 ; 0x110: 0x00000000
kfdhdb.ub4spare[10]:                0 ; 0x114: 0x00000000
kfdhdb.ub4spare[11]:                0 ; 0x118: 0x00000000
kfdhdb.ub4spare[12]:                0 ; 0x11c: 0x00000000
kfdhdb.ub4spare[13]:                0 ; 0x120: 0x00000000
kfdhdb.ub4spare[14]:                0 ; 0x124: 0x00000000
kfdhdb.ub4spare[15]:                0 ; 0x128: 0x00000000
kfdhdb.ub4spare[16]:                0 ; 0x12c: 0x00000000
kfdhdb.ub4spare[17]:                0 ; 0x130: 0x00000000
kfdhdb.ub4spare[18]:                0 ; 0x134: 0x00000000
kfdhdb.ub4spare[19]:                0 ; 0x138: 0x00000000
kfdhdb.ub4spare[20]:                0 ; 0x13c: 0x00000000
kfdhdb.ub4spare[21]:                0 ; 0x140: 0x00000000
kfdhdb.ub4spare[22]:                0 ; 0x144: 0x00000000
kfdhdb.ub4spare[23]:                0 ; 0x148: 0x00000000
kfdhdb.ub4spare[24]:                0 ; 0x14c: 0x00000000
kfdhdb.ub4spare[25]:                0 ; 0x150: 0x00000000
kfdhdb.ub4spare[26]:                0 ; 0x154: 0x00000000
kfdhdb.ub4spare[27]:                0 ; 0x158: 0x00000000
kfdhdb.ub4spare[28]:                0 ; 0x15c: 0x00000000
kfdhdb.ub4spare[29]:                0 ; 0x160: 0x00000000
kfdhdb.ub4spare[30]:                0 ; 0x164: 0x00000000
kfdhdb.ub4spare[31]:                0 ; 0x168: 0x00000000
kfdhdb.ub4spare[32]:                0 ; 0x16c: 0x00000000
kfdhdb.ub4spare[33]:                0 ; 0x170: 0x00000000
kfdhdb.ub4spare[34]:                0 ; 0x174: 0x00000000
kfdhdb.ub4spare[35]:                0 ; 0x178: 0x00000000
kfdhdb.ub4spare[36]:                0 ; 0x17c: 0x00000000
kfdhdb.ub4spare[37]:                0 ; 0x180: 0x00000000
kfdhdb.ub4spare[38]:                0 ; 0x184: 0x00000000
kfdhdb.ub4spare[39]:                0 ; 0x188: 0x00000000
kfdhdb.ub4spare[40]:                0 ; 0x18c: 0x00000000
kfdhdb.ub4spare[41]:                0 ; 0x190: 0x00000000
kfdhdb.ub4spare[42]:                0 ; 0x194: 0x00000000
kfdhdb.ub4spare[43]:                0 ; 0x198: 0x00000000
kfdhdb.ub4spare[44]:                0 ; 0x19c: 0x00000000
kfdhdb.ub4spare[45]:                0 ; 0x1a0: 0x00000000
kfdhdb.ub4spare[46]:                0 ; 0x1a4: 0x00000000
kfdhdb.ub4spare[47]:                0 ; 0x1a8: 0x00000000
kfdhdb.ub4spare[48]:                0 ; 0x1ac: 0x00000000
kfdhdb.ub4spare[49]:                0 ; 0x1b0: 0x00000000
kfdhdb.ub4spare[50]:                0 ; 0x1b4: 0x00000000
kfdhdb.ub4spare[51]:                0 ; 0x1b8: 0x00000000
kfdhdb.ub4spare[52]:                0 ; 0x1bc: 0x00000000
kfdhdb.ub4spare[53]:                0 ; 0x1c0: 0x00000000
kfdhdb.ub4spare[54]:                0 ; 0x1c4: 0x00000000
kfdhdb.ub4spare[55]:                0 ; 0x1c8: 0x00000000
kfdhdb.ub4spare[56]:                0 ; 0x1cc: 0x00000000
kfdhdb.ub4spare[57]:                0 ; 0x1d0: 0x00000000
kfdhdb.acdb.aba.seq:                0 ; 0x1d4: 0x00000000
kfdhdb.acdb.aba.blk:                0 ; 0x1d8: 0x00000000
kfdhdb.acdb.ents:                   0 ; 0x1dc: 0x0000
kfdhdb.acdb.ub2spare:                0 ; 0x1de: 0x0000

从kfed看,这个磁盘的扇区是512,OS块大小是4096,用DD拷贝第一个块就包含磁盘头的信息

[原创] ASM磁盘分区或者设备文件删除后恢复的方法

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