Data-Aware Tiering
Industry-first technology allows small- and medium-sized businesses (SMBs) to easily and affordably utilise solid state drives (SSD)
How do small and medium business (SMB) IT administrators effectively use solid state drives (SSDs) to accelerate their applications? They can't. Either the array is too expensive or the drives must be in their own pool and separate from the rest of the data. Data must be sent manually to the fast volume (SSD) or to the normal volume.
How can the IT administrator figure out what data is transactional in nature, that is, what data should be sent to the fast volume? To make things even more confusing and complicated, data can have mixed characteristics. But to get the most out of expensive SSDs, the solution must be intelligent and fully automatic—the data just needs to go to the right place automatically.
A Drobo is a single pool of drives by design. The user does not need to think about pooling drives or creating RAID groups. Also, drives of different sizes and types can be used in a Drobo. These advanced technologies make Drobos ideal for allowing SSDs and hard disk drives (HDDs) to work together optimally in the same chassis – automatically!
To enable use of drives of different sizes, the Drobo virtualisation layer (see BeyondRAID section) sits on top of the physical drives. Because Drobos are data aware, data is placed intelligently in the best place on the drives. With the introduction of SSD support in the Drobo B1200i, Drobo 5N, Drobo 5D, and Drobo Mini, SSDs provide a faster tier of storage for data that is transactional in nature, the type of data that benefits from the faster write and access speeds SSDs provide.
How It Works
Data-Aware Tiering on the Drobo B1200i is the first and only totally automated way for small and medium businesses to affordably utilise SSDs to accelerate their application performance. It involves zero configuration and shows immediate results. An ESG Lab Validation Report documents hands-on evaluation and testing of the Drobo B1200i.
SSD Support
With the introduction of SSD support in the Drobo B1200i, SSDs provide a faster tier of storage for data that is transactional in nature, the type of data that benefits from the faster write and access speeds SSDs provide. As data enters the Drobo, if it is transactional, then the data is written to the "transactional" tier comprised of SSDs. If the data is a sequential stream, it is written to the “bulk tier” comprised of hard disk drives (HDDs). Unlike enterprise arrays with auto-tiering, transactional data goes directly to SSDs, which ensures that BOTH writes AND reads are optimised.
Being Data Aware
As data enters the Drobo, if it is transactional, then the data is written to the faster tier of SSDs. Unlike enterprise arrays with auto-tiering, transactional data goes directly to SSDs, which ensures that BOTH writes AND reads are optimised.
As data is being written to the Drobo, transactional data (shown in red) is written
to the faster tier and other data is written to the bulk tier.
Drobo's tiering functionality allows you to store any type of data on the Drobo and the data that can be optimised by SSDs is automatically optimised in flight. This means that all data—mixed data types from 10 or more VMs in a vSphere cluster, Exchange databases/datastores, backup data, or files on a file server—automatically goes to the right place.
One Pool, Multiple Tiers
As detailed in the BeyondRAID section, a Drobo is a single pool of drives. Whether you put three drives or 12 drives in a Drobo, they are all part of the same disk pack.
Two tiers of storage automatically configured in the same Drobo disk pack.
Whether you have 8 HDDs and 2 SSDs or 9 HDDs and 3 SSDs, they will be utilised appropriately without any upfront setup. All the administrator has to do is put the drives in the Drobo.
Fully Automated Tuning
After data is written to storage, data patterns often change. Sometimes a large amount of data is written to storage and not read for weeks or even months. On the other hand, it is not uncommon for a small amount of data to be written and accessed very frequently.
With Drobo's automated tiering, optimisation of data doesn't stop when the data reaches a transactional or bulk storage tier. As the stored data is being read off the Drobo, the data is patterned and optimised in the background. Data that becomes hot will be moved to the transactional tier and visa versa. If data on the bulk tier is frequently read and begins to look more like transactional data, it will be migrated to the transactional tier. If data on the transactional tier becomes "cold" with very few or no read requests, it will be migrated to the bulk tier. These migrations occur in the background when the storage is not under high load and do not require any administrative interaction.
When data becomes "cold" it is migrated to the bulk tier.
When data becomes "hot" it is migrated to the transactional tier.
Tiering Without SSDs
Even when a Drobo doesn't contain SSDs, Drobo still puts its automatic tiering feature to work. Without SSDs, the advantage of tiering is to eliminate the write penalty when parity data is created.
As discussed in the BeyondRAID section, a Drobo can automatically have zones of different types. Even when all HDDs in the Drobo are the same, Drobo lays out zones differently on the transactional tier than it does on the bulk tier.
Drobo creates different zone types on transactional and bulk tiers
to tune the storage appropriately for hot and cold data.
For example, mirror zones are more optimised for writes and stripes are more optimised for capacity. Leveraging BeyondRAID technology, zones are automatically created and altered on the fly to optimise the Drobo for the type of data you store on it.
Just Add SSDs … Really!
If your Drobo contains only HDDs, but if your applications need even more performance, all you have to do is introduce SSDs to the Drobo. The SSDs then become the transactional tier and all of the HDDs are delegated to the bulk tier. The only administrative task is to insert new drives into the Drobo.
Tiering is for Professionals Too!
While automated data tiering helps IT administrators accelerate business critical applications, it is also ideal for accelerating the applications you need to run faster on YOUR computer too. If you ever wished that database-driven applications such as Aperture, Lightroom, or iTunes were a bit snappier, Drobo is here to help.
Since just a little bit of high-speed flash goes a long way to accelerate your storage, we added an additional drive bay to the Drobo 5D and Drobo Mini. It’s called the Drobo Accelerator Bay and it accepts an industry-standard mSATA SSD. Since these very compact SSDs are being used in the new Ultrabook family of portable computers, they are becoming readily available and very affordable. So you can add flash to your Drobo without consuming one of the standard drive bays, which are best used to maximise capacity.
Tiering on Smaller Drobos
On the larger Drobo B1200i, there are enough drive bays to create two tiers of storage while still maintaining high capacity. On 4- and 5-bay Drobo devices, there are not enough bays to create two tiers of storage, so we had to implement tiering differently.
The mSATA SSD is used to accelerate smaller and random reads from the Drobo, while the HDDs are used for storing and streaming larger data such as photos, video, and user documents.