ASM磁盘头的前4K主要用来记录磁盘的信息，非常重要，强烈建议生产环境上做好日常备份。
备份方法：
1、 dd if=/dev/oracleasm/disks/OCRVOTE of=/backup/asmdiskheader_backup_ocrvote.txt bs=4096 count=1
2、 kfed read /dev/oracleasm/disks/OCRVOTE > /backup/asmdiskheader_bak_ocrvote_kfed.bak bs=4096 count=1
这里/dev/oracleasm/disks/OCRVOTE是ASM磁盘组OCRVOTE盘的路径
[grid@rac1 ~]$ sqlplus /nolog
SQL> conn /as sysasm
Connected.
SQL> col name for a30
SQL> col path for a30
SQL> select name,path from v$asm_disk;
NAME PATH
—————————— ——————————
DATA ORCL:DATA
FRA ORCL:FRA
OCRVOTE ORCL:OCRVOTE
这里的ASM盘的路径为ORCL:OCRVOTE，对应的实际路径在/dev/oracleasm/disks/OCRVOTE,这里“ORCL:”映射“/dev/oracleasm/disks/”
dd备份：
[grid@rac1 ~]$ dd if=/dev/oracleasm/disks/OCRVOTE of=/apps/backup/asmdiskheader_bak_OCRVOTE.txt bs=4096 count=1
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 7.4e-05 seconds, 55.4 MB/s
[grid@rac1 ~]$ ll /apps/backup/asmdiskheader_bak_OCRVOTE.txt
-rw-r–r– 1 grid oinstall 4096 Mar 10 19:32 /apps/backup/asmdiskheader_bak_OCRVOTE.txt
[grid@rac1 ~]$
kfed备份：
[grid@rac1 ~]$ ll /apps/backup/asmdiskheader_kfed_bak_OCRVOTE.bak
-rw-r–r– 1 grid oinstall 6590 Mar 10 19:35 /apps/backup/asmdiskheader_kfed_bak_OCRVOTE.bak
