I’m reminded that when I do what I do best and don’t try to be all things to all people, I get much more accomplished. Interestingly, I’ve found that the same approach applies to server storage system controllers – and to the home PC I use for photo editing.
The question many of us face is whether it’s best to use an integrated or discrete solution. Think digital television. Do you want a TV with an integrated DVD player, or do you prefer a feature-rich, dedicated player that you can upgrade and replace independent of the TV? I’ve pondered a similar question many times when considering my PC: Do I use a motherboard with an integrated graphics controller or go with a discrete graphics adapter card.
If I look only at initial costs and am satisfied with the performance of my display for day-to-day computing activities, I could go with the integrated controller, something that many consumers do. But my needs aren’t that simple. I need multiple displays, higher screen resolution, higher display system performance, and the ability to upgrade and tune the graphics to my applications. To do these things, I go with a separate discrete graphics controller card.
Hardware RAID delivers enterprise-class data protection and features
In the datacenter, IT architects often face the choice between hardware RAID, a discrete solution, and software RAID, hardware RAID’s integrated counterpart. Hardware RAID offers enterprise-class robustness and features, such as higher performance without operating systems (OS) and application interference, particularly in compute-intensive RAID 5 and RAID 6 application environments. Also, hardware-based RAID can help optimize the performance and scalability of the SAS protocol. Sure, the build of materials (BOM) costs with hardware RAID are higher when a RAID on Chip or IOC component enters the mix, but these purpose-built solutions are designed to deliver performance and flexibility unmatched by most software RAID solutions.
Enterprise-hardened RAID solutions that protect data, manage and deliver high availability can scale up and down because they are based on RAID-on-chip (ROC) solutions, and they are designed to provide a consistent experience and boot across OS’s and BIOS.
One of the biggest differences between hardware and software RAID is in data protection. For example, if the OS shuts down in the middle of a write, once it is back up the OS can’t recognize whether the write was compromised or failed because the RAID cache was from host memory. A hardware RAID solution holds the write data in separate, non-volatile cache and completes the write when the system comes back online. Even more subtly, the CPU and storage cache are offloaded from the host memory, freeing up resources for application performance.
Software RAID cost rises as features added
For software RAID to deliver write cache and advanced features, a non-volatile write cache via battery or flash backup schemes needs to be added, and suddenly the BOM costs are similar or higher than the more flexible hardware RAID solution.
In the end, LSI enterprise hardware RAID solutions bring many features and capabilities that simply cannot exist in a software RAID on-load environment. To be sure, an enterprise server is no PC or TV, but the choice between a discrete and integrated solution, whether in consumer electronics or storage server technology, is of a kindred sort. I always feel gratified when we can help one of our customers make the best choice.
For more information about our enterprise RAID solutions please visit us at http://www.lsi.com/solutions/Pages/enterpriseRAID.aspx