IDC estimates that the cost of operating a piece of IT equipment over a four year period can be up to four times greater than the initial cost of acquiring the product. This is a sobering statistic for administrators evaluating the cost of deploying a solution into an enterprise environment.
Expanders add another layer of hidden costs by incurring additional OpEX to the storage solution. Internal and external SAS expanders add upfront costs to the purchase, require power to function, and generate heat. SAS Expanders also require more cabling and take up space, effectively reducing the amount of storage that can be crammed directly into the server chassis. Building expanders directly onto the PCB of the RAID controller also increases cost and power consumption.
The Series 7 controllers will also work with expanders to provide up to 256 devices, but the option of forgoing internal and external expanders in many applications is an attractive feature that reduces the overall footprint.
Even more concerning is that SAS expanders incur latency and bandwidth penalties, hampering the performance of the solution. Largely overlooked in the past, with HDDs simply not providing enough speed, the performance limitations of expanders have remained hidden. With the changing dynamics of SSD accelerated infrastructure, these restrictions are becoming more visible.
Performance challenges can be partially overcome by leveraging dual-port SAS devices through an expander. However, this limits the selection of devices, and there is still an expander adding to the footprint and complexity of the deployment.
maxView Storage Manager
There are a number of ways to manage the ASR-72405, but we found the maxView Storage Manager GUI to be a lightweight user-friendly application that provides administrators with all of the functionality needed to manage the adapter. The web-based GUI can be viewed in standard desktop browsers without the need for a separate software installation. The utility features a wide range of compatibility and allows for management of direct attached or networked storage. The manger also provides full monitoring of an installed supercap and the AFM status.
The maxView Storage Manager provides advanced monitoring statistics along with SMART and temperature data. The documentation for the program is thorough and easily accessible from within the application. The only feature that we feel could be improved upon is a status monitor for ongoing tasks, such as RAID initialization and rebuilds, and a means of initializing multiple drives simultaneously.
The Series 7 adapters allow three configuration options for attached volumes with the addition of FlexConfig. This aids ease of configurability, with the option for automatic setup for both physical and logical volumes.
Physical drive mode: This configures the drive in a pass-through configuration, much like an HBA. There will be no addition of metadata to the drive and no use of the DRAM caching.
Simple volume mode: This allows the drive to utilize the DRAM caching and configures metadata onto the drive. This value added proposition gives HBA functionality with DRAM caching and the protection of supercaps (if attached).
RAID: Provides the full set of options for manually configuring all RAID parameters.