Before using vSCSI storage

Before using virtual SCSI (vSCSI) attached storage in your environment, ensure that your environment is configured correctly.

Considerations

Be aware of these considerations when using vSCSI attached storage.

For vSCSI attachments, the supported multipathing software driver solutions are AIX® path control module (PCM), EMC PowerPath, and Subsystem Device Driver Path Control Module (SDDPCM) 2.6.6.0 or later.
The number of volumes that can be attached to a virtual machine is not limited by PowerVC. However, each virtual machine's operating system limits how many volumes its vSCSI driver supports.
PowerVM® supports migration only between Virtual I/O Servers that use the same multipathing software driver solution.
For EMC storage, see Planning for EMC PowerMax storage.

Before using vSCSI attached storage, perform the following steps.

Turn off SCSI reserves for volumes being discovered on all the Virtual I/O Servers being used for vSCSI connections. This is required for live partition mobility (LPM) operations and for dual VIOS.
For the IBM® Storwize® family, IBM System Storage® DS8000®, and EMC using the AIX PCM model, you must run the following command on every Virtual I/O Server where vSCSI operations will be run:
```
chdef -a reserve_policy=no_reserve -c disk -s fcp -t mpioosdisk
```
For System Storage DS8000, you must run the following command on every Virtual I/O Server where vSCSI operations will be run:
```
chdef -a reserve_policy=no_reserve -c disk -s fcp -t aixmpiods8k
```
You must configure all zoning between the Virtual I/O Server and the storage device ports. This allows vSCSI environments to be imported easily and allows you to use any number of fabrics with vSCSI. For instructions, see Configuring zoning for vSCSI.
When using Hitachi ODM attributes in the Virtual I/O Server, you must run the following command on every Virtual I/O Server where vSCSI operations will be run:
```
chdef -a reserve_policy=no_reserve -c disk -s fcp -t htcvspmpio
```
.