Tiered storage is gaining momentum because of the ease in which storage systems make it possible for organizations to implement it. One way that storage system providers offer this feature is through the automated redistribution of volumes on an appropriate tier of disk according to preset policies. However since tiered storage’s introduction, new customer requirements for managing it have emerged that dictate tiered storage software found on storage systems get smarter while at the same time making it easier for users to manage.
Using native storage system software to automate the redistribution of data on the appropriate tier of storage within them started in earnest this past decade. Driven primarily by the difficulty and labor involved with implementing tiered storage at the host level and the economic benefits that organizations can derive from using a mix of FC and SATA disk drives within a storage system, it only made sense for storage systems such as the 3PAR InServ Storage Server to offer tools that automate data mobility across disk tiers.
One method used to implement tiered storage is through the policy based tiering of data. Specific policies are assigned to storage system volumes so that data within that volume is always placed on a specific tier or tiers of disk to meet some combination of application availability and performance requirements. Administrators can then set policies so that these volumes are moved from one tier of disk to another tier in anticipation of current or future applications needs.
Normally, these types of data migrations are either not possible or extremely complex as they involve time consuming and often disruptive data migrations that move the volume from one tier of disk to another and then back again.
However, using a feature such as Dynamic Optimization that is found on 3PAR InServ Storage Servers, administrators can with single command move infrequently accessed data that is stored on SATA disk to higher performing FC disk in anticipation of end of quarter or end of year processing and then move it back to SATA disk once this processing is done.
They can also use it to non-disruptively accomplish other tasks such as data lifecycle management by changing the volume’s underlying RAID levels, subsystem failure protection levels, drive types, and radial placement of data or increasing the stripe width across disks and controller resources, thereby aligning storage costs with the value of the data being served.
It is because of these types of capabilities that Dynamic Optimization has become one of the most popular tools on the 3PAR InServ Storage Server among its customers in the four (4) years since Dynamic Optimization’s 2005 release. However during that span of time, many of 3PAR’s customers have grown their 3PAR storage implementation which has created new opportunities for tiered storage functionality.
Specifically, as customers added more storage capacity in the form of disk drives to a storage system, they might also want to take advantage of the additional performance benefits that these new disk drives can deliver. The 3PAR array is architected in such a way that as resources are added to the system, the performance of all volumes improves.
To achieve this, the volume needs to span as many disk drives in the storage system as possible – existing and new. While accomplishing this is simply done with Dynamic Optimization, 3PAR saw an opportunity for policy management and multi-volume automation to further accelerate such tasks.
The availability of Policy Advisor for 3PAR’s Dynamic Optimization feature provides for policies to be set around volume layout and can launch optimizations for hundreds of volumes with a single command, redistributing the data on each volume across both existing and new disks. Policy Advisor helps organizations in several important ways:
- Users set policies by storage tier. Policy Advisor allows the user to set thresholds, above which volumes will be targeted for redistribution across newly available resources. This can be specified for each storage tier within the InServ.
- It analyzes all of the volumes configured on the array and prioritizes how to proceed. Before Dynamic Optimization redistributes a volume, Policy Advisor analyzes the existing volumes. Once this analysis is complete, it generates a report that identifies which of the existing volumes, based on pre-set policies, would most benefit from a dynamic redistribution of data across the new and existing disk drives and in what order volume redistribution should occur.
- Automate the optimization or customize when and on what volumes the optimization occurs. Once Policy Advisor completes its analysis, the user can launch in a single command the optimization of all identified volumes which would benefit from redistribution. Alternatively, organizations can schedule the optimization to occur in any of a number of alternative ways. For instance, they can schedule it to run during scheduled maintenance windows or to only optimize a subset of volumes that would most benefit from optimization.
Moving tiered storage software from the host servers to external storage systems earlier this decade resulted in the broader adoption of tiered storage software at the storage system level by organizations as a whole. While data mobility still limits tiered storage deployments on a variety of platforms, for those vendors making it simple to implement, non-disruptive and completely automated, user interest in this technology is growing significantly.
However data storage technology is a rapidly changing space and what was innovative a few years ago can often benefit from additional breakthroughs in virtualization and automation technology. Tiered storage software is no exception from this basic truth in technology.
The introduction of Policy Advisor from 3PAR for Dynamic Optimization on its InServ Storage Servers represents a significant step forward in the evolution of tiered storage software in the following way: in order for tiered storage software on storage systems to stay relevant in changing or high growth environments like the virtual data center, policy management and multi-volume automation are critical.
Policy Advisor enables 3PAR’s Dynamic Optimization software and tier management to move to the next level on its InServ Storage Systems. Tiered storage software gets smarter, it remains easy for organizations to implement and use on an ongoing basis and it gives organizations the flexibility to grow without having to “manage” storage.