如上图所示：hdisk0支持reserve_policy，而hdisk1却不支持reserve_policy。
在AIX系统上，构建ASM磁盘共享的RAC环境，需要设置reserve_policy。
安装rac要将reserve_lock（reserve_policy）设置成NO或no_reserve，目的是因为RAC 需要 并发的共享盘 ，所以盘不能被一台机器锁住
如果不设置说不上什么时候会出问题。
操作：
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To enable simultaneous access to a disk device from multiple nodes, you must set the appropriate Object Data Manager (ODM) attribute listed in the following table to the value shown, depending on the disk type:
Disk Type Attribute Value
SSA, FAStT, or non-MPIO-capable disks reserve_lock no
ESS, EMC, HDS, CLARiiON, or MPIO-capable disks
reserve_policy no_reserve
To determine whether the attribute has the correct value, enter a command similar to the following on all cluster nodes for each disk device that you want to use:
# /usr/sbin/lsattr -E -l hdiskn
If the required attribute is not set to the correct value on any node, then enter a command similar to one of the following on that node:
■ SSA and FAStT devices
# /usr/sbin/chdev -l hdiskn -a reserve_lock=no
■ ESS, EMC, HDS, CLARiiON, and MPIO-capable devices
# /usr/sbin/chdev -l hdiskn -a reserve_policy=no_reserve
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