Another benefit of automated tiering is that weekly or monthly workloads can be granted the benefit of fast disk only when they actually need it. As a monthly batch job progresses and the responsible databases start churning for a 24-hour period, they will reap the benefits of the SSD-backed storage, then fall back to the slower disk as their processing completes. Another example might be a virtual desktop infrastructure that experiences heavy loads during the morning log-ins and the evening log-offs, when desktop VMs are being quickly spun up and put away, respectively, with lower disk I/O utilization in the middle.
Performance in numbers Automated tiering isn't completely new to Dell EqualLogic, but the ability to extend the tiering across multiple high-speed and low-speed arrays such as the PS6100XV and the PS4100E puts the performance benefits in bold relief. Rather than having to add three or four arrays of differing storage types to fully realize the benefits, the 6100XVS accomplishes much the same goal internally, as it can drive both SSD and SAS drives in a single 24-disk 2U chassis. And demonstrating the effects of storage tiering is relatively simple, requiring only a repetitive workload that extends for a reasonable period of time.
Using IOMeter to test the PS6100XV and the PS4100E arrays was the simplest way to investigate the solution. When hit with a mix of streaming and random reads and writes, the throughput grew substantially in some cases, less so in others, depending on a wide variety of variables such as block size and the level of random reads and writes. As with any storage device, your mileage may vary depending on the workload, but my general-purpose testing shows that the combination of the PS6100XV and the PS4100E should adapt very nicely to most infrastructures.
By extending automated storage tiering throughout the EqualLogic product line, Dell has made it both simpler and less costly to implement an extremely useful storage management capability in the data center.
This story, "Review: Dell EqualLogic SANs make the most of automated tiering," was originally published at InfoWorld.com. Follow the latest developments in storage, data management, and data protection at InfoWorld.com.
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