ASM磁盤頭的前4K主要用來記錄磁盤的信息，非常重要，強烈建議生產環境上做好日常備份。
備份方法：
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
這裏/dev/oracleasm/disks/OCRVOTE是ASM磁盤組OCRVOTE盤的路徑
[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$asm_disk;
NAME PATH
------------------------------ ------------------------------
DATA ORCL:DATA
FRA ORCL:FRA
OCRVOTE ORCL:OCRVOTE
這裏的ASM盤的路徑爲ORCL:OCRVOTE，對應的實際路徑在/dev/oracleasm/disks/OCRVOTE,這裏"ORCL:"映射"/dev/oracleasm/disks/"
dd備份：
[grid@rac1 ~]$ 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備份：
[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