Unix Study-- AIX system to build RAC through ASM disk

Unix Study--AIX System Building RAC via ASM Disk Sharing

As shown above, hdisk0 supports reserve_policy, while hdisk1 does not.

On AIX systems, to build an RAC environment for ASM disk sharing, reserve_policy needs to be set.

RAC is installed by setting reserve_lock (reserve_policy) to NO or no_reserve, so that disks cannot be locked by one machine because RAC requires concurrent shared disks

If you don't set it, you don't know when it's going to go wrong.

Operation:

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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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