對oracle asm 磁碟組進行檢查

     在oracle 11gR2的版本中，新增一個命令，可以對正常mount的磁碟組進行檢查，這對我們去維護asm方式的資料庫提供了很多便利

有以下場合非常適用:

1:主機伺服器例行維護，需要重啟主機和資料庫，這時如果不進行檢查的話，很有可能出現asm例項磁碟組載入不成功，導致嚴重的事故。

    例如磁碟頭損壞等，這個時候在重啟前我們加以檢查的話，就可以發現問題，及時預警，做資料備份等。

測試如下:

模擬磁碟頭損壞
[grid@12cdb1 ~]$ dd if=/dev/zero of=/dev/sde1 bs=4096 count=1
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 0.000932074 s, 4.4 MB/s
[grid@12cdb1 ~]$
[grid@12cdb1 ~]$
[grid@12cdb1 ~]$ kfed read /dev/sde1|more
kfbh.endian:                          0 ; 0x000: 0x00
kfbh.hard:                            0 ; 0x001: 0x00
kfbh.type:                            0 ; 0x002: KFBTYP_INVALID
kfbh.datfmt:                          0 ; 0x003: 0x00
kfbh.block.blk:                       0 ; 0x004: blk=0
kfbh.block.obj:                       0 ; 0x008: file=0
kfbh.check:                           0 ; 0x00c: 0x00000000
kfbh.fcn.base:                        0 ; 0x010: 0x00000000
kfbh.fcn.wrap:                        0 ; 0x014: 0x00000000
kfbh.spare1:                          0 ; 0x018: 0x00000000
kfbh.spare2:                          0 ; 0x01c: 0x00000000
000000000 00000000 00000000 00000000 00000000  [................]
  Repeat 255 times
KFED-00322: Invalid content encountered during block traversal: [kfbtTraverseBlock][Invalid OSM block type][][0]




asm例項中進行檢查:

SQL> alter diskgroup dgtest check;

Diskgroup altered.




這時我們檢視asm例項中日誌資訊:

可以看到紅色部分就顯示不能讀取磁碟頭資訊，這個時候我們就要介入處理了。

SQL> alter diskgroup dgtest check
Tue Jul 22 17:54:47 2014
ERROR: Could not read the header of disk DGTEST_0000 (0).
NOTE: process _user12084_+asm (12084) initiating offline of disk 0.3914034847 (DGTEST_0000) with mask 0x7e in group 2 (DGTEST) without client assisting
NOTE: initiating PST update: grp 2 (DGTEST), dsk = 0/0xe94b6e9f, mask = 0x6a, op = clear
Tue Jul 22 17:54:47 2014
GMON updating disk modes for group 2 at 24 for pid 23, osid 12084
ERROR: disk 0(DGTEST_0000) in group 2(DGTEST) cannot be offlined because the disk group has external redundancy.
Tue Jul 22 17:54:47 2014
ERROR: too many offline disks in PST (grp 2)
Tue Jul 22 17:54:47 2014
ERROR: Failed to offline disk DGTEST_0000 (0).
NOTE: starting check of diskgroup DGTEST
Tue Jul 22 17:54:48 2014
ASM Health Checker found 1 new failures
Tue Jul 22 17:54:48 2014
ASM Health Checker found 1 new failures
Tue Jul 22 17:54:48 2014
GMON checking disk 0 for group 2 at 25 for pid 23, osid 12084

修改磁碟頭後，我們再次做檢查
沒有任何報錯

SQL> alter diskgroup dgtest check
Tue Jul 22 18:07:50 2014
NOTE: starting check of diskgroup DGTEST
Tue Jul 22 18:07:51 2014
GMON checking disk 0 for group 2 at 26 for pid 23, osid 12084
Tue Jul 22 18:07:53 2014
SUCCESS: check of diskgroup DGTEST found no errors
Tue Jul 22 18:07:53 2014
SUCCESS: alter diskgroup dgtest check