disk_repair_time

不一樣的天空w發表於2017-08-10


Oracle 10g引入了ASM,在10g版本中,如果由於故障(光纜故障,控制器故障,HBA卡故障或者其他故障造成磁碟無法訪問),這時Oracle會把這個磁碟drop掉。在11g中,Oracle引入了一個引數disk_repair_time,這個引數與"Oracle ASM Fast Mirror Resync"有關,有了這個特性,當故障發生時(除磁碟自身故障),在disk_repair_time時間之內,待故障解決磁碟線上後,Oracle會同步由於故障而暫時沒有寫入本磁碟extent的資料,而不必同步磁碟上所有的資料,進而避免因此造成的效能問題。如果超過disk_repair_time時間,系統仍未修復,Oracle會drop這個磁碟。預設時間為3.6小時,一般能滿足大多數環境,可以根據實際情況設定這個引數。


使用這個特性,要滿足兩個條件:

 1.磁碟組的COMPATIBLE屬性版本至少在11.1及以上(磁碟組COMPATIBLE引數影響到磁碟組的格式,後設資料,AU等)
 2.磁碟組的的冗餘模式為Normal或High
 
注意:如果是磁碟自身故障(DG冗餘模式為Norma/High),這個磁碟必須drop,新增磁碟後,oracle會自動reblancing。如果冗餘模式為external,磁碟出故障時,磁碟組會離線,要透過備份來恢復資料庫。Exadata冗餘度至少為Normal,是透過在ASM級別中mirror,所以等cell節點任何一個節點down機,不影響資料庫的正常使用。

本文透過在11g ASM中建立一磁碟組db2,然後將磁碟組中一塊盤offline,超過disk_repair_time後,觀察磁碟的變化

ASMCMD> lsattr -G db2 -l
Name                     Value
access_control.enabled   FALSE
access_control.umask     066
au_size                  1048576
cell.smart_scan_capable  FALSE
compatible.asm           11.2.0.0.0
compatible.rdbms         10.1.0.0.0
disk_repair_time         3.6h
sector_size              512

ASMCMD> setattr -G db2 disk_repair_time 5h
ORA-15032: not all alterations performed
ORA-15242: could not set attribute disk_repair_time
ORA-15283: ASM operation requires compatible.rdbms of 11.1.0.0.0 or higher (DBD ERROR: OCIStmtExecute)
注意:compatible引數至少為11.1

ASMCMD> setattr -G db2 compatible.rdbms 11.2
ASMCMD> lsattr -G db2 -l
Name                     Value
access_control.enabled   FALSE
access_control.umask     066
au_size                  1048576
cell.smart_scan_capable  FALSE
compatible.asm           11.2.0.0.0
compatible.rdbms         11.2
disk_repair_time         3.6h
sector_size              512


為了測試,設定disk_repair_time為5分鐘,m代表分鐘,h代表小時,如果不輸單位,預設是小時

ASMCMD> setattr -G db2 disk_repair_time 5m
ASM alert後臺日誌

SQL> /* ASMCMD */ALTER DISKGROUP DB2 SET ATTRIBUTE 'disk_repair_time' = '5m'
SUCCESS: /* ASMCMD */ALTER DISKGROUP DB2 SET ATTRIBUTE 'disk_repair_time' = '5m'

ASMCMD> lsattr -G db2 -l

Name                     Value
access_control.enabled   FALSE
access_control.umask     066
au_size                  1048576
cell.smart_scan_capable  FALSE
compatible.asm           11.2.0.0.0
compatible.rdbms         11.2
disk_repair_time         5m
sector_size              512
ASMCMD>

檢視磁碟組的資訊和磁碟頭資訊
ASMCMD> lsdsk -G db2
Path
/dev/oracleasm/disks/ASMDISK11
/dev/oracleasm/disks/ASMDISK13

ASMCMD> lsdsk -G db2 --statistics

Reads  Write  Read_Errs  Write_Errs  Read_time  Write_Time  Bytes_Read  Bytes_Written  Voting_File  Path
  191   1068          0           0    .965827    39.09044     1794048        4374528            N  /dev/oracleasm/disks/ASMDISK11
  166   1068          0           0   1.040196   38.521265      684032        4374528            N  /dev/oracleasm/disks/ASMDISK13
ASMCMD>
[oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK11
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: blk=0
kfbh.block.obj:              2147483648 ; 0x008: disk=0
kfbh.check:                  1549816565 ; 0x00c: 0x5c6052f5
kfbh.fcn.base:                        0 ; 0x010: 0x00000000
kfbh.fcn.wrap:                        0 ; 0x014: 0x00000000
kfbh.spare1:                          0 ; 0x018: 0x00000000
kfbh.spare2:                          0 ; 0x01c: 0x00000000
kfdhdb.driver.provstr:ORCLDISKASMDISK11 ; 0x000: length=17
kfdhdb.driver.reserved[0]:   1145918273 ; 0x008: 0x444d5341
kfdhdb.driver.reserved[1]:    827020105 ; 0x00c: 0x314b5349
kfdhdb.driver.reserved[2]:           49 ; 0x010: 0x00000031
kfdhdb.driver.reserved[3]:            0 ; 0x014: 0x00000000
kfdhdb.driver.reserved[4]:            0 ; 0x018: 0x00000000
kfdhdb.driver.reserved[5]:            0 ; 0x01c: 0x00000000
kfdhdb.compat:                186646528 ; 0x020: 0x0b200000
kfdhdb.dsknum:                        0 ; 0x024: 0x0000
kfdhdb.grptyp:                        2 ; 0x026: KFDGTP_NORMAL
kfdhdb.hdrsts:                        3 ; 0x027: KFDHDR_MEMBER
kfdhdb.dskname:                DB2_0000 ; 0x028: length=8
kfdhdb.grpname:                     DB2 ; 0x048: length=3
kfdhdb.fgname:                 DB2_0000 ; 0x068: length=8
kfdhdb.capname:                         ; 0x088: length=0
kfdhdb.crestmp.hi:             33036942 ; 0x0a8: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.crestmp.lo:           3147311104 ; 0x0ac: USEC=0x0 MSEC=0x20a SECS=0x39 MINS=0x2e
kfdhdb.mntstmp.hi:             33036942 ; 0x0b0: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.mntstmp.lo:           3163762688 ; 0x0b4: USEC=0x0 MSEC=0xcc SECS=0x9 MINS=0x2f
kfdhdb.secsize:                     512 ; 0x0b8: 0x0200
kfdhdb.blksize:                    4096 ; 0x0ba: 0x1000
kfdhdb.ausize:                  1048576 ; 0x0bc: 0x00100000
kfdhdb.mfact:                    113792 ; 0x0c0: 0x0001bc80
kfdhdb.dsksize:                    2447 ; 0x0c4: 0x0000098f
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]:                0 ; 0x0da: 0x0000
kfdhdb.redomirrors[2]:                0 ; 0x0dc: 0x0000
kfdhdb.redomirrors[3]:                0 ; 0x0de: 0x0000
kfdhdb.dbcompat:              168820736 ; 0x0e0: 0x0a100000
kfdhdb.grpstmp.hi:             33036942 ; 0x0e4: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.grpstmp.lo:           3147119616 ; 0x0e8: USEC=0x0 MSEC=0x14f SECS=0x39 MINS=0x2e
kfdhdb.vfstart:                       0 ; 0x0ec: 0x00000000
kfdhdb.vfend:                         0 ; 0x0f0: 0x00000000
kfdhdb.spfile:                        0 ; 0x0f4: 0x00000000
kfdhdb.spfflg:                        0 ; 0x0f8: 0x00000000

[oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK13
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: blk=0
kfbh.block.obj:              2147483649 ; 0x008: disk=1
kfbh.check:                  1549816567 ; 0x00c: 0x5c6052f7
kfbh.fcn.base:                        0 ; 0x010: 0x00000000
kfbh.fcn.wrap:                        0 ; 0x014: 0x00000000
kfbh.spare1:                          0 ; 0x018: 0x00000000
kfbh.spare2:                          0 ; 0x01c: 0x00000000
kfdhdb.driver.provstr:ORCLDISKASMDISK13 ; 0x000: length=17
kfdhdb.driver.reserved[0]:   1145918273 ; 0x008: 0x444d5341
kfdhdb.driver.reserved[1]:    827020105 ; 0x00c: 0x314b5349
kfdhdb.driver.reserved[2]:           51 ; 0x010: 0x00000033
kfdhdb.driver.reserved[3]:            0 ; 0x014: 0x00000000
kfdhdb.driver.reserved[4]:            0 ; 0x018: 0x00000000
kfdhdb.driver.reserved[5]:            0 ; 0x01c: 0x00000000
kfdhdb.compat:                186646528 ; 0x020: 0x0b200000
kfdhdb.dsknum:                        1 ; 0x024: 0x0001
kfdhdb.grptyp:                        2 ; 0x026: KFDGTP_NORMAL
kfdhdb.hdrsts:                        3 ; 0x027: KFDHDR_MEMBER
kfdhdb.dskname:                DB2_0001 ; 0x028: length=8
kfdhdb.grpname:                     DB2 ; 0x048: length=3
kfdhdb.fgname:                 DB2_0001 ; 0x068: length=8
kfdhdb.capname:                         ; 0x088: length=0
kfdhdb.crestmp.hi:             33036942 ; 0x0a8: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.crestmp.lo:           3147311104 ; 0x0ac: USEC=0x0 MSEC=0x20a SECS=0x39 MINS=0x2e
kfdhdb.mntstmp.hi:             33036942 ; 0x0b0: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.mntstmp.lo:           3163762688 ; 0x0b4: USEC=0x0 MSEC=0xcc SECS=0x9 MINS=0x2f
kfdhdb.secsize:                     512 ; 0x0b8: 0x0200
kfdhdb.blksize:                    4096 ; 0x0ba: 0x1000
kfdhdb.ausize:                  1048576 ; 0x0bc: 0x00100000
kfdhdb.mfact:                    113792 ; 0x0c0: 0x0001bc80
kfdhdb.dsksize:                    2447 ; 0x0c4: 0x0000098f
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]:                0 ; 0x0da: 0x0000
kfdhdb.redomirrors[2]:                0 ; 0x0dc: 0x0000
kfdhdb.redomirrors[3]:                0 ; 0x0de: 0x0000
kfdhdb.dbcompat:              168820736 ; 0x0e0: 0x0a100000
kfdhdb.grpstmp.hi:             33036942 ; 0x0e4: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.grpstmp.lo:           3147119616 ; 0x0e8: USEC=0x0 MSEC=0x14f SECS=0x39 MINS=0x2e
kfdhdb.vfstart:                       0 ; 0x0ec: 0x00000000
kfdhdb.vfend:                         0 ; 0x0f0: 0x00000000
kfdhdb.spfile:                        0 ; 0x0f4: 0x00000000
kfdhdb.spfflg:                        0 ; 0x0f8: 0x00000000
ASMCMD> iostat -G db2
Group_Name  Dsk_Name  Reads    Writes
DB2         DB2_0000  1859584  5001216
DB2         DB2_0001  749568   5001216
ASMCMD> offline -G db2 -D DB2_0001
Diskgroup altered.
ASMCMD>

從ASM alet中可以看到磁碟將要在5分鐘後drop
WARNING: Disk 1 (DB2_0001) in group 1 will be dropped in: (300) secs on ASM inst 1
Mon Jun 20 15:55:23 2016

5分鐘後,磁碟被ASM強制刪除(alert日誌)
SQL> alter diskgroup DB2 drop disk DB2_0001 force /* ASM SERVER */
NOTE: GroupBlock outside rolling migration privileged region
NOTE: requesting all-instance membership refresh for group=1
Mon Jun 20 16:01:36 2016
GMON updating for reconfiguration, group 1 at 26 for pid 33, osid 8507
NOTE: cache closing disk 1 of grp 1: (not open) DB2_0001
NOTE: group DB2: updated PST location: disk 0000 (PST copy 0)
NOTE: group 1 PST updated.
Mon Jun 20 16:01:36 2016
NOTE: membership refresh pending for group 1/0xe0485f13 (DB2)
GMON querying group 1 at 27 for pid 19, osid 5801
NOTE: cache closing disk 1 of grp 1: (not open) _DROPPED_0001_DB2
SUCCESS: refreshed membership for 1/0xe0485f13 (DB2)
NOTE: starting rebalance of group 1/0xe0485f13 (DB2) at power 1
SUCCESS: alter diskgroup DB2 drop disk DB2_0001 force /* ASM SERVER */
SUCCESS: PST-initiated drop disk in group 1(3762839315))
Starting background process ARB0
Mon Jun 20 16:01:39 2016
ARB0 started with pid=34, OS id=9355
NOTE: assigning ARB0 to group 1/0xe0485f13 (DB2) with 1 parallel I/O
NOTE: stopping process ARB0
SUCCESS: rebalance completed for group 1/0xe0485f13 (DB2)
NOTE: Attempting voting file refresh on diskgroup DB2
Mon Jun 20 16:01:43 2016
NOTE: GroupBlock outside rolling migration privileged region
NOTE: requesting all-instance membership refresh for group=1
GMON updating for reconfiguration, group 1 at 28 for pid 34, osid 9361
NOTE: cache closing disk 1 of grp 1: (not open) _DROPPED_0001_DB2
NOTE: group DB2: updated PST location: disk 0000 (PST copy 0)
NOTE: group 1 PST updated.
WARNING: offline disk number 1 has references (51 AUs)
NOTE: membership refresh pending for group 1/0xe0485f13 (DB2)
Mon Jun 20 16:01:49 2016
GMON querying group 1 at 29 for pid 19, osid 5801
NOTE: cache closing disk 1 of grp 1: (not open) _DROPPED_0001_DB2
Mon Jun 20 16:01:49 2016
SUCCESS: refreshed membership for 1/0xe0485f13 (DB2)
NOTE: Attempting voting file refresh on diskgroup DB2


可以看到磁碟組db2 offline_disks顯示為1

ASMCMD> lsdg
State    Type    Rebal  Sector  Block       AU  Total_MB  Free_MB  Req_mir_free_MB  Usable_file_MB  Offline_disks  Voting_files  Name
MOUNTED  NORMAL  N         512   4096  1048576      2447     2394                0            1197              1             N  DB2/
MOUNTED  EXTERN  N         512   4096  1048576      4894     4786                0            4786              0             N  OHSDBA/
MOUNTED  NORMAL  N         512   4096  1048576      7341     6410             2447            1981              0             Y  SYSTEMDG/

ASMCMD> 

offline後,再次讀取磁碟頭部資訊(發現頭部資訊沒改變)

[oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK13
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: blk=0
kfbh.block.obj:              2147483649 ; 0x008: disk=1
kfbh.check:                  1549816567 ; 0x00c: 0x5c6052f7
kfbh.fcn.base:                        0 ; 0x010: 0x00000000
kfbh.fcn.wrap:                        0 ; 0x014: 0x00000000
kfbh.spare1:                          0 ; 0x018: 0x00000000
kfbh.spare2:                          0 ; 0x01c: 0x00000000
kfdhdb.driver.provstr:ORCLDISKASMDISK13 ; 0x000: length=17
kfdhdb.driver.reserved[0]:   1145918273 ; 0x008: 0x444d5341
kfdhdb.driver.reserved[1]:    827020105 ; 0x00c: 0x314b5349
kfdhdb.driver.reserved[2]:           51 ; 0x010: 0x00000033
kfdhdb.driver.reserved[3]:            0 ; 0x014: 0x00000000
kfdhdb.driver.reserved[4]:            0 ; 0x018: 0x00000000
kfdhdb.driver.reserved[5]:            0 ; 0x01c: 0x00000000
kfdhdb.compat:                186646528 ; 0x020: 0x0b200000
kfdhdb.dsknum:                        1 ; 0x024: 0x0001
kfdhdb.grptyp:                        2 ; 0x026: KFDGTP_NORMAL
kfdhdb.hdrsts:                        3 ; 0x027: KFDHDR_MEMBER
kfdhdb.dskname:                DB2_0001 ; 0x028: length=8
kfdhdb.grpname:                     DB2 ; 0x048: length=3
kfdhdb.fgname:                 DB2_0001 ; 0x068: length=8
kfdhdb.capname:                         ; 0x088: length=0
kfdhdb.crestmp.hi:             33036942 ; 0x0a8: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.crestmp.lo:           3147311104 ; 0x0ac: USEC=0x0 MSEC=0x20a SECS=0x39 MINS=0x2e
kfdhdb.mntstmp.hi:             33036942 ; 0x0b0: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.mntstmp.lo:           3163762688 ; 0x0b4: USEC=0x0 MSEC=0xcc SECS=0x9 MINS=0x2f
kfdhdb.secsize:                     512 ; 0x0b8: 0x0200
kfdhdb.blksize:                    4096 ; 0x0ba: 0x1000
kfdhdb.ausize:                  1048576 ; 0x0bc: 0x00100000
kfdhdb.mfact:                    113792 ; 0x0c0: 0x0001bc80
kfdhdb.dsksize:                    2447 ; 0x0c4: 0x0000098f
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]:                0 ; 0x0da: 0x0000
kfdhdb.redomirrors[2]:                0 ; 0x0dc: 0x0000
kfdhdb.redomirrors[3]:                0 ; 0x0de: 0x0000
kfdhdb.dbcompat:              168820736 ; 0x0e0: 0x0a100000
kfdhdb.grpstmp.hi:             33036942 ; 0x0e4: HOUR=0xe DAYS=0x14 MNTH=0x6 YEAR=0x7e0
kfdhdb.grpstmp.lo:           3147119616 ; 0x0e8: USEC=0x0 MSEC=0x14f SECS=0x39 MINS=0x2e
kfdhdb.vfstart:                       0 ; 0x0ec: 0x00000000
kfdhdb.vfend:                         0 ; 0x0f0: 0x00000000
kfdhdb.spfile:                        0 ; 0x0f4: 0x00000000
kfdhdb.spfflg:                        0 ; 0x0f8: 0x00000000
SQL> select name, path from v$asm_disk;
NAME                                     PATH
---------------------------------------- ------------------------------------------------------------
                                         /dev/oracleasm/disks/ASMDISK14
                                         /dev/oracleasm/disks/ASMDISK13
_DROPPED_0001_DB2
DB2_0000                                 /dev/oracleasm/disks/ASMDISK11
OHSDBA_0001                              /dev/oracleasm/disks/ASMDISK10
OHSDBA_0000                              /dev/oracleasm/disks/ASMDISK9
DATA_PGOLD_0004                          /dev/oracleasm/disks/ASMDISK8
DATA_PGOLD_0003                          /dev/oracleasm/disks/ASMDISK7
DATA_PGOLD_0002                          /dev/oracleasm/disks/ASMDISK6
DATA_PGOLD_0001                          /dev/oracleasm/disks/ASMDISK5
DATA_PGOLD_0000                          /dev/oracleasm/disks/ASMDISK4

NAME                                     PATH
---------------------------------------- ------------------------------------------------------------
SYSTEMDG_0002                            /dev/oracleasm/disks/ASMDISK3
SYSTEMDG_0001                            /dev/oracleasm/disks/ASMDISK2
SYSTEMDG_0000                            /dev/oracleasm/disks/ASMDISK1

14 rows selected.
SQL>


被drop後,再次嘗試online disk

ASMCMD>  online -G db2 -D DB2_0001
ORA-15032: not all alterations performed
ORA-15054: disk "DB2_0001" does not exist in diskgroup "DB2" (DBD ERROR: OCIStmtExecute)
ASMCMD>


嘗試undrop disk,雖然沒報什麼錯誤,但是磁碟仍舊沒能撤回成功

[oracle@ohs1 ~]$ sqlplus / as sysasm
SQL*Plus: Release 11.2.0.3.0 Production on Mon Jun 20 16:50:17 2016
Copyright (c) 1982, 2011, Oracle.  All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
With the Real Application Clusters and Automatic Storage Management options
SQL> alter diskgroup db2 undrop disks;
Diskgroup altered.
SQL>

SQL> alter diskgroup db2 undrop disks
NOTE: GroupBlock outside rolling migration privileged region
NOTE: requesting all-instance membership refresh for group=2
Mon Jun 20 16:50:35 2016
GMON updating for reconfiguration, group 2 at 17 for pid 28, osid 16254
NOTE: cache closing disk 1 of grp 2: (not open) _DROPPED_0001_DB2
NOTE: group DB2: updated PST location: disk 0000 (PST copy 0)
NOTE: group 2 PST updated.
Mon Jun 20 16:50:36 2016
NOTE: membership refresh pending for group 2/0xfb327d85 (DB2)
GMON querying group 2 at 18 for pid 19, osid 13443
NOTE: cache closing disk 1 of grp 2: (not open) _DROPPED_0001_DB2
SUCCESS: refreshed membership for 2/0xfb327d85 (DB2)
NOTE: starting rebalance of group 2/0xfb327d85 (DB2) at power 1
SUCCESS: alter diskgroup db2 undrop disks
Starting background process ARB0
Mon Jun 20 16:50:38 2016
ARB0 started with pid=29, OS id=16331
NOTE: assigning ARB0 to group 2/0xfb327d85 (DB2) with 1 parallel I/O
NOTE: stopping process ARB0
SUCCESS: rebalance completed for group 2/0xfb327d85 (DB2)
NOTE: Attempting voting file refresh on diskgroup DB2
Mon Jun 20 16:50:41 2016
NOTE: GroupBlock outside rolling migration privileged region
NOTE: requesting all-instance membership refresh for group=2
GMON updating for reconfiguration, group 2 at 19 for pid 29, osid 16336
NOTE: cache closing disk 1 of grp 2: (not open) _DROPPED_0001_DB2
NOTE: group DB2: updated PST location: disk 0000 (PST copy 0)
NOTE: group 2 PST updated.
WARNING: offline disk number 1 has references (51 AUs)
NOTE: membership refresh pending for group 2/0xfb327d85 (DB2)
Mon Jun 20 16:50:48 2016
GMON querying group 2 at 20 for pid 19, osid 13443
NOTE: cache closing disk 1 of grp 2: (not open) _DROPPED_0001_DB2
Mon Jun 20 16:50:48 2016
SUCCESS: refreshed membership for 2/0xfb327d85 (DB2)
NOTE: Attempting voting file refresh on diskgroup DB2

ASMCMD> lsdg
State    Type    Rebal  Sector  Block       AU  Total_MB  Free_MB  Req_mir_free_MB  Usable_file_MB  Offline_disks  Voting_files  Name
MOUNTED  EXTERN  N         512   4096  1048576     12235    10514                0           10514              0             N  DATA_PGOLD/
MOUNTED  NORMAL  N         512   4096  1048576      2447     2394                0            1197              1             N  DB2/
MOUNTED  EXTERN  N         512   4096  1048576      4894     4786                0            4786              0             N  OHSDBA/
MOUNTED  NORMAL  N         512   4096  1048576      7341     6410             2447            1981              0             Y  SYSTEMDG/

ASMCMD>

NAME                           PATH
------------------------------ ------------------------------------------------------------
                               /dev/oracleasm/disks/ASMDISK14
                               /dev/oracleasm/disks/ASMDISK13
_DROPPED_0001_DB2
DB2_0000                       /dev/oracleasm/disks/ASMDISK11
OHSDBA_0001                    /dev/oracleasm/disks/ASMDISK10
OHSDBA_0000                    /dev/oracleasm/disks/ASMDISK9
DATA_PGOLD_0004                /dev/oracleasm/disks/ASMDISK8
DATA_PGOLD_0003                /dev/oracleasm/disks/ASMDISK7
DATA_PGOLD_0002                /dev/oracleasm/disks/ASMDISK6
DATA_PGOLD_0001                /dev/oracleasm/disks/ASMDISK5
DATA_PGOLD_0000                /dev/oracleasm/disks/ASMDISK4

NAME                           PATH
------------------------------ ------------------------------------------------------------
SYSTEMDG_0002                  /dev/oracleasm/disks/ASMDISK3
SYSTEMDG_0001                  /dev/oracleasm/disks/ASMDISK2
SYSTEMDG_0000                  /dev/oracleasm/disks/ASMDISK1

14 rows selected.
SQL>


因為offline被drop後,磁碟頭部資訊並未改變,所以再次新增原來的磁碟時出現錯誤

SQL> alter diskgroup db2 add disk '/dev/oracleasm/disks/ASMDISK13';
alter diskgroup db2 add disk '/dev/oracleasm/disks/ASMDISK13'
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15033: disk '/dev/oracleasm/disks/ASMDISK13' belongs to diskgroup "DB2"

SQL>


清除ASM磁碟頭部資訊,重新新增磁碟

[oracle@ohs1 ~]$ dd if=/dev/zero of=/dev/oracleasm/disks/ASMDISK13 bs=1024 count=1
1+0 records in
1+0 records out
1024 bytes (1.0 kB) copied, 0.00966501 seconds, 106 kB/s

[oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK13
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
B7F60200 00000000 00000000 00000000 00000000  [................]
  Repeat 255 times
KFED-00322: Invalid content encountered during block traversal: [kfbtTraverseBlock][Invalid OSM block type][][0]

[oracle@ohs1 ~]$ sqlplus / as sysasm
SQL*Plus: Release 11.2.0.3.0 Production on Mon Jun 20 17:13:37 2016
Copyright (c) 1982, 2011, Oracle.  All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
With the Real Application Clusters and Automatic Storage Management options

SQL> alter diskgroup db2 add disk '/dev/oracleasm/disks/ASMDISK13';
Diskgroup altered.
SQL>
注意:磁碟被drop後,磁碟頭部沒有變化,如果磁碟本身沒有問題,還想再利用這個盤,必須清除磁碟頭部才能重新新增。


Reference
Oracle ASM Fast Mirror Resync

disk group attribute




======================================================================
%E4%BB%8B%E7%BB%8D/

DISK_REPAIR_TIME介紹

1. 介紹
當ASM磁碟被drop後,ASM就會發起重平衡,保證被drop的磁碟裡涉及的extent再次冗餘,但是ASM的重平衡很費時間,並且涉及到大量其它磁碟的IO操作。但是有時侯磁碟可能會因為維護或其它原因暫時offline了,如果短時間的offline就發生重平衡,並且磁碟加回來時,又要發生重平衡,這有點不可接受。所以ASM提供了快速磁碟同步特性,在磁碟OFFLINE期間,ASM記錄OFFLINE磁碟涉及的extent,而當磁碟恢復時,ASM會快速同步這個磁碟上發生變化的extent。
如果磁碟OFFLINE很長時間,這其實是有風險的,因為在NORMAL冗餘的情況下,OFFLINE磁碟涉及的extent就只有一份了,所以ASM提供了一個磁碟組屬性DISK_REPAIR_NAME,表明在這個磁碟組上的磁碟,OFFLINE多長時間後就被DROP,ASM開始重平衡,這個值預設是3.6小時。
如果是有計劃磁碟OFFLINE維護,3.6小時也許不夠,比如Exadata的Cell節點升級,所以可能需要先將該值調大。

--在磁碟組正常情況下,設定該值的命令如下:
    
SQL> ALTER DISKGROUP DATA SET ATTRIBUTE 'disk_repair_time'= '36h';

但是如果磁碟已經被offline,那如何設定offline的磁碟多長時間drop呢?命令有些不同。


2. 判斷多少時間後磁碟被drop
--在ASM的alert日誌裡檢視,磁碟被drop掉之前的倒數計時,如下:

WARNING: Disk 0 (DATA_CD_00_DMORLCEL08) in group 1 will be dropped in: (12960) secs on ASM inst 1
WARNING: Disk 1 (DATA_CD_01_DMORLCEL08) in group 1 will be dropped in: (12960) secs on ASM inst 1
WARNING: Disk 2 (DATA_CD_02_DMORLCEL08) in group 1 will be dropped in: (12960) secs on ASM inst 1

--檢查DISK_REPAIR_NAME
SQL> column name format a30
SQL> column value format a30
SQL> select name,value from v$asm_attribute where group_number=1 and name like '%disk_repair_time%';
 
NAME                           VALUE
------------------------------ ------------------------------
disk_repair_time               3.6h


3. 延長DISK_REPAIR_TIME
--如果一個failgroup失敗,failgroup上的磁碟已經全部OFFLINE了,可以使用如下命令延長DISK_REPAIR_TIME
    
SQL> ALTER DISKGROUP <DISKGROUP NAME> OFFLINE DISKS IN FAILGROUP <FAILGROUP NAME> DROP AFTER 5H;

--然後再檢查ASM的alert日誌,是否生效,例如:
    
WARNING: Disk 2 (DATA_CD_02_DMORLCEL08) in group 1 will be dropped in: (18000) secs on ASM inst 1
WARNING: Disk 3 (DATA_CD_03_DMORLCEL08) in group 1 will be dropped in: (18000) secs on ASM inst 1
WARNING: Disk 4 (DATA_CD_04_DMORLCEL08) in group 1 will be dropped in: (18000) secs on ASM inst 1
WARNING: Disk 5 (DATA_CD_05_DMORLCEL08) in group 1 will be dropped in: (18000) secs on ASM inst 1

--如果只有1塊盤offline,命令如下:
    
SQL> ALTER DISKGROUP <DISKGROUP NAME> OFFLINE DISK <DISK NAME> DROP AFTER 5H;

--檢查磁碟名稱
SQL> col path format a59
SQL> set lines 200
SQL> set pagesi 400
SQL> select path, name, header_status, mode_status, mount_status, state, failgroup from v$asm_disk order by path;


4. 立即drop磁碟
--如果磁碟的修復時間預計比較長,那可以立即drop掉磁碟,開始重平衡,而不是等完DISK_REPAIR_TIME時間後再開始。

如果failgroup失敗,命令如下:
    
ALTER DISKGROUP <DISKGROUP NAME> DROP DISKS IN FAILGROUP <FAILGROUP NAME> FORCE;

如果某塊磁碟失敗,命令如下:
    
ALTER DISKGROUP <DISKGROUP NAME> DROP DISK <DISK NAME> FORCE;


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