3 Things to Consider for Better Performance with Auto TieringBy Kyle Christopher

It’s time to start rethinking traditional approaches to tiering. The trends have changed a lot. NetApp, for example, now recommends putting exchange on SATA drives when 5 years ago that would have been unthinkable. With the way things are moving in terms of the sheer amount of data being stored, it’s causing us to rethink the traditional tiering categories.

Many IT professionals understand the traditional approach to tiering data storage. Tiered storage is a data storage environment consisting of two or more kinds of storage defined by differences in at least one of these four attributes: price, performance, capacity and function. Any significant difference in one or more of the four defining attributes can be sufficient to justify a separate storage tier. In the past this was done manually.

Auto tiering, on the other hand, is the process by which data is automatically moved around between tiers of storage. Nowadays this is usually referred to as “smart storage.” In a nutshell, smart storage “learns” the bits and bytes that are being accessed more frequently than others and moves them to higher speed storage tiers. For example, if you have a SQL database that people are using frequently to access part numbers, the system automatically moves those bits onto a higher speed drive. This might be hardware or software operating as an application between the storage layer and the host layer. This means that if people are frequently looking for part numbers in that database, the system will move that information to an area that can be accessed more quickly since it is needed more often.

Most folks are already aware of the most common tiers:

Tier 0: SSD Drives (Solid State Drives), which are the fastest
Tier 1: 15K Drives, next fastest
Tier 2: 10K
Tier 3: 7.2 K drives, which are often referred as SATA drives (Serial ATA).

It’s time to rethink the traditional approach to auto tiering. Here are three things you need to consider when assessing your options for auto tiering. 

1. Enterprise Plus Licensing May Be a Requirement

Many vendors require you to have enterprise plus licensing with VMware to be able to support the third-party multipathing plugins. Granted, with 5.1 this has changed. But if you’re not on 5.1 you need to make sure you have a version of vSphere that supports the multipathing plugins. Your SAN array is moving volumes around and if your multipathing module is not installed, you don’t know where that volume just went. In other words, just lost your virtual machine connectivity. Not good.

2. Auto tiering Can Save You or Cost You Money

Whether it saves or costs you money will depend on the size of your environment. Do you really need to be running everything on 15K disks? Additionally, with the way systems are now set up, you’re pushing more data and applications to lower speed drives that have higher capacity. A lot of people are rethinking traditional categories of applications and where those applications reside.

3. You Can Intermix SSD with SATA Drives for Better Performance

The current storage trend is to mix the two edge tiers together; SSD with SATA drives. SSD gives you the caching performance you need while SATA drives give you the capacity. As you may know, the higher the capacity is, the slower the speed, and vice versa. For example, we see this with Nimble or Tintri storage devices. Likewise, with NetApp and EMC gear, you now have Dell EqualLogic storage arrays that combine SATA and SSDs within the same shelf. This is becoming more commonplace. As software gets smarter, this trend will continue. We’re able to move data in and out of SSD more efficiently now while getting the I/O needed in just a few disks. In the past, several dozen 15K drives were needed for the same performance level.

Conclusion

To summarize, you need to consider your licensing and your environment as well as how you may be able to use your current gear more efficiently. The landscape has changed and will continue to do so. The goal is to stay ahead of the curve, utilizing your smart storage options and putting in place a solution that could save you a lot of money while helping your current environment run a lot more efficiently. What has been your experience with auto tiering? Tell us your story.