Storage technologies for IBM Db2 Warehouse

A key decision that you must make for your Db2® Warehouse deployment is the type of storage technology to set up and use.

Db2 Warehouse can run multiple parallel engines. Each engine accesses independent file sets for an optimized, shared-nothing pattern that helps provide high performance.

A Db2 Warehouse MPP deployment requires a POSIX-compliant cluster file system, which provides servers and other resources with concurrent access to a single file system. Examples of a POSIX-compliant cluster file system are IBM Spectrum Scale (formerly IBM® General Parallel File System, or GPFS) and VxFS, which you mount on /mnt/clusterfs, as shown in Cluster file system.

Choose the storage technology that best satisfies your business requirements and constraints, for example:

Cost. How much does it cost to purchase and operate?
Scaling capabilities. How fast and easy is it to add or remove resources as needed?
Ease of operation. Is it easy to set up and administer?
Performance. How fast can it access data?
Protection. Does it keep your data secure?
Attachment method. Should the nodes be attached a network-attached storage (NAS) device or to a storage area network (SAN)? For more information, see Table 1.

Table 1. Comparison of NAS versus SAN
	Network-attached storage (NAS)	Storage area network (SAN)
Description	NAS is a dedicated file storage device that is connected to a network that allows data to be stored in and retrieved from a central location.	A SAN is a dedicated network that connects all storage devices so that they work as a single storage block.
Ease of deployment	NAS is easier to deploy on an existing architecture.	Deployment of a SAN requires more knowledge of communication protocols and extra cluster file system configuration.
Performance	NAS is usually slower because it typically shares data within the communications network.	A SAN provides excellent speed and performance because it is a dedicated storage network.
Data access	NAS provides file-level data access.	A SAN provides block-level data access.
Protocols	Files are shared and stored by using standard file system protocols, mainly NFS.	Communication protocols for a SAN include Fibre Channel and iSCSI.
Deployment of a Db2 Warehouse container	In a NAS environment, because the storage is already configured, deploying a Db2 Warehouse container is straightforward.	In a SAN environment, you must configure storage devices to deploy a Db2 Warehouse container.
Other traits	NAS offers ease of use and management.	The ability to scale capacity is one of the main reasons for using a SAN.