9.1 Storage Requirements for DST Volume Pairs

Volumes in a shadow volume pair can reside on any device that is seen as local to the DST server, such as direct-attached storage and Fibre Channel SAN devices. For information about using iSCSI SAN devices, see Section 9.1.2, iSCSI Block Storage Devices.

Block storage devices used for the primary and secondary storage can have different performance characteristics. Typically, the secondary storage area is slower and less expensive.

Dynamic Storage Technology supports using target iSCSI block storage devices to store the primary and secondary volumes in a shadow volume pair. Any iSCSI block storage device should work in a shadow volume pair, if it is compatible with the Linux iSCSI initiator software running on the OES server where you create and manage the shadow volume pair. However, only iSCSI targets running on the following OES servers (or later versions) have been tested and are supported for OES 11 SP1 and later:

For information about setting up iSCSI target devices on OES servers, see Setting Up an iSCSI LIO Target Server in the SLES 12 Storage Administration Guide.

The iSCSI targets are connected by using the Linux iSCSI initiator software on the OES server where you are creating DST shadow volumes. For information about configuring iSCSI initiators and discovering iSCSI target devices, see Configuring iSCSI Initiator in the SLES 12 Storage Administration Guide.

Dynamic Storage Technology supports using two OES Storage Services (NSS) volumes in a shadow volume pair.

For information about using NSS features and file system attributes while the NSS volumes are in a shadow volume pair, see Section 9.4, Using NSS Volumes in DST Shadow Volume Pairs.