1M AU：510
2M AU：1022
4M AU：2046
8M AU：4094
16M AU：8190
32M AU：16382
64M AU：32766
通过下面的脚本可获取备份磁盘头的block number
SQL> col compatibility for a11
SQL> col database_compatibility for a11
col path for a30
SQL> SQL> set pages 156 lines 156
col header_backup_location for a70
SQL> SQL> select 'kfed read '||path||' ausz='||allocation_unit_size||' blknum='||((allocation_unit_size/block_size)*2-2) header_backup_location from v$asm_disk a,v$asm_diskgroup b where a.group_number=b.group_number and a.group_number !=0;
HEADER_BACKUP_LOCATION
----------------------------------------------------------------------
kfed read /dev/oracleasm/disks/ASMDISK14 ausz=16777216 blknum=8190 kfed read /dev/oracleasm/disks/ASMDISK10 ausz=16777216 blknum=8190 kfed read /dev/oracleasm/disks/ASMDISK9 ausz=4194304 blknum=2046 kfed read /dev/oracleasm/disks/ASMDISK3 ausz=1048576 blknum=510 kfed read /dev/oracleasm/disks/ASMDISK2 ausz=1048576 blknum=510 kfed read /dev/oracleasm/disks/ASMDISK1 ausz=1048576 blknum=510
6 rows selected.
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
With the Real Application Clusters and Automatic Storage Management options
在AU大小为1M,4M,16M下查看，字段kfbh.type内容为KFBTYP_DISKHEAD，表示为磁盘头部
[oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK14 ausz=16777216 blknum=8190|grep kfbh.type kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD [oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK14 ausz=16777216 blknum=0|grep kfbh.type kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD [oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK14 ausz=16777216 blknum=8190|grep kfbh.type kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD [oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK9 ausz=4194304 blknum=0 |grep kfbh.type kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD [oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK9 ausz=4194304 blknum=2046|grep kfbh.type kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD [oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK1 ausz=1048576 blknum=0|grep kfbh.type kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD [oracle@ohs1 ~]$ kfed read /dev/oracleasm/disks/ASMDISK1 ausz=1048576 blknum=510|grep kfbh.type kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD [oracle@ohs1 ~]$
获取ASM磁盘头备份位置的脚本
col compatibility for a11 col database_compatibility for a11 col path for a30 set pages 156 lines 156 col header_backup_location for a70 select 'kfed read '||path||' ausz='||allocation_unit_size||' blknum='||((allocation_unit_size/block_size)*2-2) header_backup_location from v$asm_disk a,v$asm_diskgroup b where a.group_number=b.group_number and a.group_number !=0;
col compatibility for a11
col database_compatibility for a11
col path for a30
set pages 156 lines 156
col header_backup_location for a70
select mount_status,header_status,mode_status,a.state,redundancy,b.sector_size,block_size,allocation_unit_size au_size,compatibility,database_compatibility,'kfed read '||path||' ausz='||allocation_unit_size||' blknum='||((allocation_unit_size/block_size)*2-2) header_backup_location from v$asm_disk a,v$asm_diskgroup b
where a.group_number=b.group_number
and a.group_number !=0;
Reference
http://www.dbform.com/html/2012/1875.html
