Virtualization with ONStor Clustered NAS

By Deni Connor
Principal Analyst
September 2008

Virtualization of file services using ONStor clustered network-attached storage (NAS) systems and gateways lets enterprise datacenter customers leverage their existing storage investments, meet service level agreements and boost their operational efficiencies, cost-effectively.

ONStor File Services Virtualization

ONStor’s virtualization capability, enabled via virtual servers (vServers) and its Global Name Space (GNS) technology – provides for the consolidation of physical file servers and NAS devices into a single storage environment that allows IT managers to remap users and applications to storage resources, scale processing power and capacity, migrate data and increase resource utilization — all without disrupting user operations.

The company’s Global Name Space (GNS) spans and aggregates all the file systems under management on ONStor Clustered NAS filers, gateways and Microsoft Windows file servers and converges them into a unified pool of information that can be managed from a single console. By abstracting data from its physical location, GNS is able to present a single logical image to users and applications, thus shielding them from the addition, removal or migration of filers and file servers within the cluster.

Once the storage environment is virtualized using GNS, virtual servers (vServers) can be carved out and logically mapped to individual applications and users much like is done in compute layer virtualization with VMware. The ONStor virtual server (vServer) is simply a logical instance of a physical file server to which IT managers can assign an IP address, security authentication and storage resources. This abstraction of the physical environment is isolated and protected from other virtual servers in the environment.

Benefits of ONStor Virtualization

There are many benefits that accrue from implementing ONStor vServer and GNS environments. Among them are:

• Server consolidation and better resource utilization;
• Performance and capacity scaling;
• Load balancing, workload management, migration and improved maintenance;
• Improved data migration, protection and high-availability; and,
• Consolidated management.

Let’s look at each of these possible benefits.

Server Consolidation and Better Resource Utilization

With vServers, the data stores for a variety of departments can be consolidated onto a smaller number of physical systems, allowing for better capacity utilization. In consolidating physical servers with vServer technology, hardware utilization is also increased and datacenter rackspace, as well as power and cooling are reduced.

Performance and Capacity Scaling

With ONStor’s virtualization capability, IT administrators can easily add new file servers or NAS devices to the cluster non-disruptively. Because each node in the cluster maintains a log of the cluster information and database, changes to the cluster can be made transparently to the user.

Because new gateways and virtual servers can be added to form an N-way cluster (currently limited to eight nodes), this gives the IT administrator the ability to scale almost infinitely to multiple petabytes of information. New gateways and virtual servers also allow for increased performance, as traffic is load-balanced and virtualized over several appliances.

Load Balancing, Workload Management, Migration and Improved Maintenance

Without user disruption, nodes can be removed from the ONStor Cluster when they need to be repaired, patched or upgraded. Application workloads running on the node can be manually or automatically shifted from one node to another without disrupting file services.  As new nodes or repaired nodes are introduced into the cluster, workload is again reassigned transparently to users. Conversely, as nodes are removed from the cluster, their workload is re-distributed throughout the cluster.

With the capabilities of GNS and vServers, IT administrators can scale up capacity and move file systems from one NAS head to another without disrupting operations on the network. They can, for instance, create policies that will divert traffic to a different NAS head if a particular NAS head is saturated. This policy-making capability provides a ready means for load balancing and flexibility.

The encapsulation of virtual server instances also promotes the migration of one virtual server to another – again without disruption to user operations. Because network resources – IP addresses, VLANs, memory and CPU are encapsulated in a virtual server, when migration needs to occur for patching, repair or configuration changes, the container can be moved simply via a drag and drop operation and settings maintained.

Improved Data Protection and High-Availability

ONStor’s virtualization eases backing up and protecting the data center infrastructure. With ONStor’s vServer technology, IT managers can create inexpensive gateways in the same cluster as production gateways. When backing up the data on the cluster, vServers are moved from the production gateway to the new gateway and backed up from there, where backup operations will not impact production systems.

Data can also be migrated between different tiers of heterogeneous storage and by applying a data protection policy to an ONStor cluster, snapshotting, mirroring, data replication, high-availability are facilitated.

With snapshot capability, a file system or block of data can be snapped and only changed blocks retained. Data can be mirrored asynchronously over Fibre Channel or IP. If one node in the cluster is deemed dead, file services can automatically failover to the remaining NAS heads and the file system redirects the mount points automatically so that from an end-user standpoint everything is transparent.

IT can also quickly recover from a disaster by bringing the nodes back up individually and moving the file systems around. All information that is relevant to file systems, the global namespace, files or virtual servers is maintained by the individual nodes, so data recovery is fast.

Single-Pane-of-Glass Management

Integrated with each ONStor system is a management interface called the ONStor NAS Cluster Manager or Gateway Manager that leverages vServer and GNS technology to monitor individual nodes, entire clusters or even discrete file systems. The management interface also provides great flexibility for IT and C-level management – what an individual can view, monitor or change can be determined by permissions the IT manager sets.

Using ONStor’s virtualization capabilities, IT administrators can easily provision one or more virtual servers from the NAS cluster. They can collect multiple physical file servers, aggregate them and carve out virtual instances that act much like a physical server. ONStor virtualizes the IP, protocol and file system stacks in such a way that IT can garner the benefits of virtualization.

A separate optional management module provides trending data and can monitor and report on information gathered from the cluster.

SSG-NOW Assessment

ONStor’s value is based on its heterogeneous, open storage architecture and its clustered, virtualized file system. The company’s clustered NAS solutions, which focus on the benefits of file server and file system virtualization, are truly next-generation products. ONStor’s GNS virtualization technology lets users access data independent of its physical location, simplifies the movement of data between file servers and protects and manages it. Its’ vServer technology is truly a way to grow capacity independent of performance and let customers maximize their investments and preserve and give new life to existing systems.

When ONStor’s products are used for file server consolidation, with the virtualizing GNS and vServers, customers can easily grow their businesses and rely on a single vendor’s equipment – and, they can do it cost-effectively.