Dell PS Series Storage Expansion Comparison, Expansion activity, Traditional DAS and SAN, january

DELL PS Series architecture

A look-up and transfer mechanism is used to efficiently track and process pages located on the group members. When a PS Series group receives a client server request, it identifies the location of the data and transfers the request to the member that contains the data. A request may be transferred one more time if the desired data is located on another member.

The entire page lookup and transfer operation increases latency insignificantly relative to the disk access time. In addition, the PS Series Architecture’s optimization technology continually adjusts storage placement and network connections to optimize performance.

Fast, Simple Provisioning and Scaling

Using the scalability model from the PS Series Architecture, a PS Series group can scale linearly in both capacity and performance — all while the system remains online. The model allows for multiple members in a single group, with a controlled and efficient addition of resources as new members are added.

Individually, each member is a fully-functional, high-performance, highly-available storage array with mirrored write-back caches and multiple storage network connections. Resources like disks, controllers, caches, and network connections can be easily added and removed from a group with no complex administration tasks or impact on availability.

As capacity and performance requirements increase, a group can be expanded. New members “learn” configuration and performance information from the group — with no manual administrative intervention. Data and application server connection load balancing occur automatically as the group scales. Data access activity is monitored, and data and network connections are adjusted as needed automatically and online.

The scalability model allows for automated, online expansion in all storage dimensions, and the PS Series Architecture nearly eliminates downtime caused by expanding or managing a storage system. Because capacity can be added so easily, IT managers need to buy only the storage necessary for today’s applications, easing budget constraints caused by excessive and superfluous purchases. Upgrades to new technologies are done easily as different types of PS Series arrays can interoperate in the same PS Series group at the same time.

Table 1 shows how the scalability model of the PS Series Architecture compares to traditional DAS and SAN solutions.

Expansion activity	Traditional DAS and SAN	PS Series Architecture
Add storage capacity or network bandwidth	Limited expansion capabilities are available	Add another member to a group; data
		remains available
Increase network connections	Requires repetitive manual tasks	Minimal administrative effort is required
Add controllers	Storage must be taken offline; data is	Expansion occurs online; data remains available
	not available
Perform load balancing	Requires repetitive manual tasks; data	Operation is fully automated; data
	may not be available	remains available

Table 1: Storage Expansion Comparison

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