Maxxan switch makes storage virtualization easy

Just as Ethernet networking devices have evolved from straightforward hubs to layer 2 switches to layer 7 application-aware switches, so are SAN switches evolving. The Maxxan MXV320 Intelligent Application Switch corresponds to a layer 7 Ethernet switch, providing application-layer functions including virtualization of storage, storage gateway capability, replication and mirroring, and snapshot-based backups.

The replication functions are especially noteworthy. They make it possible to create mirrored or replicated storage or snapshot backups in a vendor-neutral manner, using any backup or storage management software desired, even with a multivendor SAN. This is a tremendous benefit in large organizations with multivendor SANs. It is, as far as I know, a totally unique offering.

The Virtual Route

The MXV320 is a chassis-based FC (Fibre Channel) switch that can support up to 320 1Gbps FC ports or 160 2Gbps FC ports. It also supports two intelligent storage blades, the SG210m and SA200f. The SG210m is a Windows Storage Server-based gateway that can make any FC storage attached through the SG210m switch available as Windows file-server storage. The SA200f provides both Windows and NFS (Network File System) NAS functionality, plus easily accessible storage replication, mirroring, and virtualization.

The blade has a Web-based management application that monitors fan speeds, temperatures, and power supplies, plus a serial console for initial configuration. The SANCruiser application manages the switch hardware, most hardware management for the blade, and provides a topological view of the entire SAN and its management functions. Finally, the SA200f runs a Linux kernel and the IPStor application for storage virtualization, NAS, mirroring, replication, and backup functions.

Storage virtualization adds a layer of abstraction between actual storage devices and host computers. This means that the volume seen by a host can actually be made up of blocks from multiple devices, either local or remote. The SA200f switch ports can act as either target or initiator ports, so they can act as storage devices to a host and as a host to the storage devices. However, the ports must be set manually to target mode or left in the default initiator mode -- they don't switch automatically.

IPStor’s nice wizard setup makes it simple to control virtual storage. The Add Storage wizard can virtualize, service-enable, unassign or import storage, while the Virtualize wizard enables virtualization, reformatting a disk or disks to add a virtualization header. The Service-enable wizard uses the virtual header on another disk to create a virtual virtual disk so existing data isn't lost. The Import wizard reads header info from volumes that have already been virtualized on another switch, which comes in handy when moving existing resources to a new switch.

Management capabilities are excellent for the virtual SAN functions, though administrators will still need to use separate vendor-supplied applications to administer the various devices in the SAN. Virtual disks can be created from multiple devices from multiple vendors, enabling a truly flexible SAN environment. Once virtual disks are created, you can set up replication and mirroring. Replication can happen when a set threshold of data has been changed, at set times, or at given intervals. The application will scan for differences so a full replication isn't necessary over a WAN link -- a mirror can be created, shipped to a remote site, and replication will handle the differences.