Setting the reserve policy attributes of a device

In some configurations, you must consider the reservation policy of the device on the Virtual I/O Server.

The following table explains the situations in which the reservation policy of the device on the Virtual I/O Server is important for systems that are managed by the Hardware Management Console (HMC) and the Integrated Virtualization Manager (IVM).

Table 1. Situations where the reservation policy of a device is important
HMC-managed systems	IVM-managed systems
To use an Multipath I/O (MPIO) configuration at the client, none of the virtual SCSI devices on the Virtual I/O Server can be reserving the virtual SCSI device. For Live Partition Mobility, the reserve attribute on the physical storage that is used by the mobile partition must be set to no reserve for the mobile partition to access it from both the source and destination servers. For PowerVM™ Active Memory™ Sharing, the Virtual I/O Server automatically sets the reserve attribute on the physical volume to no reserve when you add a paging space device to the shared memory pool.	For Live Partition Mobility, the reserve attribute on the physical storage that is used by the mobile partition must be set to no reserve for the mobile partition to access it from both the source and destination servers.

In these configurations, you need to ensure that the reserve_policy attribute of the device is set to no_reserve.

From a Virtual I/O Server logical partition, list the disks (or paging space devices) to which the Virtual I/O Server has access. Run the following command:
```
lsdev -type disk
```
To determine the reserve policy of a disk, run the following command, where hdiskX is the name of the disk that you identified in step 1. For example, hdisk5.
```
lsdev -dev hdiskX -attr reserve_policy
```
If the reserve_policy value is anything other than no_reserve, it must be changed so that you can use the disk in any of the above configurations. The results might look similar to the following:
```
..
reserve_policy  no_reserve                       Reserve Policy                   True
```
To set the reserve_policy to no_reserve, run the following command, where hdiskX is the name of the disk for which you want to set the reserve_policy attribute to no_reserve.
```
chdev -dev hdiskX -attr reserve_policy=no_reserve
```
Repeat this procedure from the other Virtual I/O Server logical partition. Although the reserve_policy attribute is an attribute of the device, each Virtual I/O Server saves the value of the attribute. You must set the reserve_policy attribute from both Virtual I/O Server logical partitions so that both Virtual I/O Server logical partitions recognize that the reserve_policy of the device is set to no_reserve.