ORA-15042 故障終極恢復----惜分飛

weixin_34253539發表於2018-11-20

接到一個朋友恢復請求,19個lun的asm 磁碟組，由於其中一個lun有問題，他們進行了增加一個新lun，刪除老lun的方法操作,但是操作一半hang住了(因為壞的lun是底層損壞，無法完成rebalance),然後儲存工程師繼續修復異常lun，非常幸運異常lun修復好了，但是高興過了頭，直接從儲存上刪除了新加入的lun(已經rebalance一部分資料進去了)，這個時候asm dg徹底趴下了，不能mount成功，請求恢復支援。由於某種原因，無法從lun層面恢復，只能讓我們提供資料庫層面恢復

Mon Sep 21 19:52:35 2015
SQL> alter diskgroup  dg_XFF add disk '/dev/rhdisk116' size 716800M drop disk dg_XFF_0012
NOTE: Assigning number (1,20) to disk (/dev/rhdisk116)
NOTE: requesting all-instance membership refresh for group=1
NOTE: initializing header on grp 1 disk DG_XFF_0020
NOTE: requesting all-instance disk validation for group=1
Mon Sep 21 19:52:44 2015
NOTE: skipping rediscovery for group 1/0xb94738f1 (DG_XFF) on local instance.
NOTE: requesting all-instance disk validation for group=1
NOTE: skipping rediscovery for group 1/0xb94738f1 (DG_XFF) on local instance.
NOTE: initiating PST update: grp = 1
Mon Sep 21 19:52:44 2015
GMON updating group 1 at 25 for pid 27, osid 12124486
NOTE: PST update grp = 1 completed successfully
NOTE: membership refresh pending for group 1/0xb94738f1 (DG_XFF)
GMON querying group 1 at 26 for pid 18, osid 10092734
NOTE: cache opening disk 20 of grp 1: DG_XFF_0020 path:/dev/rhdisk116
GMON querying group 1 at 27 for pid 18, osid 10092734
SUCCESS: refreshed membership for 1/0xb94738f1 (DG_XFF)
Mon Sep 21 19:52:47 2015
SUCCESS: alter diskgroup  dg_XFF add disk '/dev/rhdisk116' size 716800M drop disk dg_XFF_0012
NOTE: starting rebalance of group 1/0xb94738f1 (DG_XFF) at power 1
Starting background process ARB0
Mon Sep 21 19:52:47 2015
ARB0 started with pid=28, OS id=10944804
NOTE: assigning ARB0 to group 1/0xb94738f1 (DG_XFF) with 1 parallel I/O
NOTE: Attempting voting file refresh on diskgroup DG_XFF
Mon Sep 21 20:35:06 2015
SQL> ALTER DISKGROUP DG_XFF MOUNT  /* asm agent *//* {1:51107:7083} */
NOTE: cache registered group DG_XFF number=1 incarn=0xdd6f975a
NOTE: cache began mount (first) of group DG_XFF number=1 incarn=0xdd6f975a
NOTE: Assigning number (1,0) to disk (/dev/rhdisk10)
NOTE: Assigning number (1,1) to disk (/dev/rhdisk11)
NOTE: Assigning number (1,2) to disk (/dev/rhdisk16)
NOTE: Assigning number (1,3) to disk (/dev/rhdisk17)
NOTE: Assigning number (1,4) to disk (/dev/rhdisk22)
NOTE: Assigning number (1,5) to disk (/dev/rhdisk23)
NOTE: Assigning number (1,6) to disk (/dev/rhdisk28)
NOTE: Assigning number (1,7) to disk (/dev/rhdisk29)
NOTE: Assigning number (1,8) to disk (/dev/rhdisk33)
NOTE: Assigning number (1,9) to disk (/dev/rhdisk34)
NOTE: Assigning number (1,10) to disk (/dev/rhdisk4)
NOTE: Assigning number (1,11) to disk (/dev/rhdisk40)
NOTE: Assigning number (1,12) to disk (/dev/rhdisk41)
NOTE: Assigning number (1,13) to disk (/dev/rhdisk45)
NOTE: Assigning number (1,14) to disk (/dev/rhdisk46)
NOTE: Assigning number (1,15) to disk (/dev/rhdisk5)
NOTE: Assigning number (1,16) to disk (/dev/rhdisk52)
NOTE: Assigning number (1,17) to disk (/dev/rhdisk53)
NOTE: Assigning number (1,18) to disk (/dev/rhdisk57)
NOTE: Assigning number (1,19) to disk (/dev/rhdisk58)
Wed Sep 30 11:08:07 2015
NOTE: start heartbeating (grp 1)
GMON querying group 1 at 33 for pid 35, osid 4194488
NOTE: Assigning number (1,20) to disk ()
GMON querying group 1 at 34 for pid 35, osid 4194488
NOTE: cache dismounting (clean) group 1/0xDD6F975A (DG_XFF)
NOTE: dbwr not being msg'd to dismount
NOTE: lgwr not being msg'd to dismount
NOTE: cache dismounted group 1/0xDD6F975A (DG_XFF)
NOTE: cache ending mount (fail) of group DG_XFF number=1 incarn=0xdd6f975a
NOTE: cache deleting context for group DG_XFF 1/0xdd6f975a
GMON dismounting group 1 at 35 for pid 35, osid 4194488
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
NOTE: Disk  in mode 0x8 marked for de-assignment
ERROR: diskgroup DG_XFF was not mounted
ORA-15032: not all alterations performed
ORA-15040: diskgroup is incomplete
ORA-15042: ASM disk "20" is missing from group number "1"
ERROR: ALTER DISKGROUP DG_XFF MOUNT  /* asm agent *//* {1:51107:7083} */

這裡比較明顯，由於儲存工程師直接刪除了lun，這裡導致磁碟組DG_XFF丟失asm disk 20，使得磁碟組無法直接mount，由於該磁碟組已經進行了較長時間的rebalance，丟失的盤中已經有大量資料（包括後設資料），因此就算修改pst讓磁碟組mount起來(不一定成功)，也會丟失大量資料，也不一定可以直接拿出來裡面的資料，如果只是加入盤，但是由於某種原因沒有做rebalance，那我們直接可以通過修改pst,使得磁碟組mount起來。因此對於這樣的情況，我們能夠做的，只能從底層掃描磁碟，生成資料檔案(因為有部分檔案的後設資料在丟失lun之上，如果直接使用現存後設資料資訊，直接拷貝，或者unload資料都會丟失大量資料），然後再進一步unload資料，完成恢復。需要恢復磁碟資訊

grp# dsk# bsize ausize disksize diskname        groupname       path
---- ---- ----- ------ -------- --------------- --------------- -------------
   1    0  4096  4096K   179200 DG_XFF_0000     DG_XFF          /dev/rhdisk10
   1    1  4096  4096K   179200 DG_XFF_0001     DG_XFF          /dev/rhdisk11
   1    2  4096  4096K   179200 DG_XFF_0002     DG_XFF          /dev/rhdisk16
   1    3  4096  4096K   179200 DG_XFF_0003     DG_XFF          /dev/rhdisk17
   1    4  4096  4096K   179200 DG_XFF_0004     DG_XFF          /dev/rhdisk22
   1    5  4096  4096K   179200 DG_XFF_0005     DG_XFF          /dev/rhdisk23
   1    6  4096  4096K   179200 DG_XFF_0006     DG_XFF          /dev/rhdisk28
   1    7  4096  4096K   179200 DG_XFF_0007     DG_XFF          /dev/rhdisk29
   1    8  4096  4096K   179200 DG_XFF_0008     DG_XFF          /dev/rhdisk33
   1    9  4096  4096K   179200 DG_XFF_0009     DG_XFF          /dev/rhdisk34
   1   10  4096  4096K   179200 DG_XFF_0010     DG_XFF          /dev/rhdisk4
   1   11  4096  4096K   179200 DG_XFF_0011     DG_XFF          /dev/rhdisk40
   1   12  4096  4096K   179200 DG_XFF_0012     DG_XFF          /dev/rhdisk41
   1   13  4096  4096K   179200 DG_XFF_0013     DG_XFF          /dev/rhdisk45
   1   14  4096  4096K   179200 DG_XFF_0014     DG_XFF          /dev/rhdisk46
   1   15  4096  4096K   179200 DG_XFF_0015     DG_XFF          /dev/rhdisk5
   1   16  4096  4096K   179200 DG_XFF_0016     DG_XFF          /dev/rhdisk52
   1   17  4096  4096K   179200 DG_XFF_0017     DG_XFF          /dev/rhdisk53
   1   18  4096  4096K   179200 DG_XFF_0018     DG_XFF          /dev/rhdisk57
   1   19  4096  4096K   179200 DG_XFF_0019     DG_XFF          /dev/rhdisk58

這次運氣比較好，丟失的磁碟組只是一個業務磁碟組，而且裡面只有19個表空間，10個分割槽表，因此在資料字典完成的情況下，恢復10個分割槽表(一共6443個分割槽)的資料，整體恢復效果如下:
RECOVER

從整體資料量看恢復比例為：6003.26953/6027.26935*100%=99.6018127%,對於丟失了一個已經rebalance的大部分的lun，依舊能夠恢復如此的資料，整體看非常理想.

如果您遇到此類情況,無法解決請聯絡我們，提供專業ORACLE資料庫恢復技術支援

原文：ORA-15042: ASM disk “N” is missing from group number “M” 故障恢復

相關文章