通过asm来存储数据库文件，在linux下可以通过asmlib的方式来管理块设备，也可以直接使用裸设备来建立asm磁盘。在asmlib方式下，磁盘设备启动顺序和名称的改变不会影响到asm的使用，但如果直接使用裸设备会怎么样那？我们知道asm会在磁盘中存储与asm有关的元数据，通过这些元数据asm可以了解磁盘的相关信息，因此理论上裸设备名称的改变不会影响asm的正常使用。下面，通过实验来验证一下。

首先看以下，裸设备的配置文件

node1

[root@node1 ~]# cat /etc/udev/rules.d/60-raw.rules 
# Enter raw device bindings here.
#
# An example would be:
#   ACTION=="add", KERNEL=="sda", RUN+="/bin/raw /dev/raw/raw1 %N"
# to bind /dev/raw/raw1 to /dev/sda, or
#   ACTION=="add", ENV{MAJOR}=="8", ENV{MINOR}=="1", RUN+="/bin/raw /dev/raw/raw2 %M %m"
# to bind /dev/raw/raw2 to the device with major 8, minor 1.

ACTION=="add", KERNEL=="sdb1", RUN+="/bin/raw /dev/raw/raw1 %N"
ACTION=="add", KERNEL=="sdb2", RUN+="/bin/raw /dev/raw/raw2 %N"
ACTION=="add", KERNEL=="sdb5", RUN+="/bin/raw /dev/raw/raw3 %N"
ACTION=="add", KERNEL=="sdb6", RUN+="/bin/raw /dev/raw/raw4 %N"
ACTION=="add", KERNEL=="sdb7", RUN+="/bin/raw /dev/raw/raw5 %N"
ACTION=="add", KERNEL=="sdb8", RUN+="/bin/raw /dev/raw/raw6 %N"
ACTION=="add", KERNEL=="sdb9", RUN+="/bin/raw /dev/raw/raw7 %N"

[root@node2 rules.d]# cat 60-raw.rules 
# Enter raw device bindings here.
#
# An example would be:
#   ACTION=="add", KERNEL=="sda", RUN+="/bin/raw /dev/raw/raw1 %N"
# to bind /dev/raw/raw1 to /dev/sda, or
#   ACTION=="add", ENV{MAJOR}=="8", ENV{MINOR}=="1", RUN+="/bin/raw /dev/raw/raw2 %M %m"
# to bind /dev/raw/raw2 to the device with major 8, minor 1.

ACTION=="add", KERNEL=="sdb1", RUN+="/bin/raw /dev/raw/raw1 %N"
ACTION=="add", KERNEL=="sdb2", RUN+="/bin/raw /dev/raw/raw2 %N"
ACTION=="add", KERNEL=="sdb5", RUN+="/bin/raw /dev/raw/raw3 %N"
ACTION=="add", KERNEL=="sdb6", RUN+="/bin/raw /dev/raw/raw4 %N"
ACTION=="add", KERNEL=="sdb7", RUN+="/bin/raw /dev/raw/raw5 %N"
ACTION=="add", KERNEL=="sdb8", RUN+="/bin/raw /dev/raw/raw6 %N"
ACTION=="add", KERNEL=="sdb9", RUN+="/bin/raw /dev/raw/raw7 %N"