Depending on who or what is your sphere of influence, or your sources of information and insight are, there will be different views of tiering, particular when it comes to tiered storage and storage tiering for cloud, virtual and traditional environments.
Recently I did piece over at 21st century IT (21cit) titled Tiered Storage Explained that looks at both tiered storage and storage tiering (e.g. movement and migration, automated or manual) that you can read here.
In the data center (or information factory) everything is not the same as different applications have various performance, availability, capacity and economics among other requirements. Consequently there are different levels or categories of service along with associated tiers of technology to support them, more on these in few moments.
Technology tiering is all around you
Tiering is not unique to Information Technology (IT) as it is more common than you may realize, granted, not always called tiering per say. For example there are different tiers of transportation (beside public or private, shared or single use) ranging from planes, trains, bicycles and boats among others.
Tiered transportation (Bikes, Trains, Planes, Gondolas)
Moving beyond IT (we will get back to that shortly), there are other examples of tiered technologies. For example I live in the Stillwater / Minneapolis Minnesota area thus have a need for different types of snow movement and management tools, after all, not all snow situations are the same.
Tiered snow movement technology (Different tools for various tasks)
The other part of the year when the snow is not actually accumulating or the St. Croix river is not frozen which on a good year can be from March to November, its fishing time. That means having different types of fishing rods rigged for various things such as casting, trolling or jigging, not to mention big fish or little fish, something like how a golfer has different clubs. While like a golfer a single fishing rod can do the task, it’s not as practical thus different tools for various tasks.
Different sizes and types of fish
Speaking of transportation and automobiles, there are also various metrics some of which have a correlation to Data Center energy use and effectiveness, not to mention EPA Energy Star for Data Centers and Data Center Storage.
Technology tiering in and around the data center
Now let’s get back to technology tiering the data center (or information factory) including tiered storage and storage tiering (here’s link to the tiered storage explained piece I mentioned earlier). The three primary building blocks for IT services are processing or compute (e.g. servers, workstations), networking or connectivity and storage that include hardware, software, management tools and applications. These resources in turn get accessed by yes you guessed it, different tiers or categories of devices from mobile smart phones, tablets, laptops, workstations or terminals browsers, applets and other presentation services.
Lets focus on storage for a bit (pun intended)
Keep in mind that not everything is the same in the data center from a performance, availability, capacity and economic perspective. This means different threat risks to protect applications and data against, performance or space capacity needs among others.
Avoid treating all threat risks the same, tiered data protection
Part of modernizing data protection is aligning various tools and technologies to meet different requirements including Recovery Time Objectives (RTO) and Recovery Point Objectives (RPO) along with Service Level Agreements (SLAs) and Service Level Objectives (SLO’s).
In addition to protecting data and applications to meet various needs, there are also tiered storage mediums or media (e.g. HDD, SSD, Tape) along with storage systems.
Excerpt, Chapter 9: Storage Services and Systems from my book Cloud and Virtual Data Storage Networking book (CRC Press) available via Amazon (also Kindle) and other venues.
9.2 Tiered Storage
Tiered storage is often referred to by the type of disk drives or media, by the price band, by the architecture or by its target use (online for files, emails and databases; near line for reference or backup; offline for archive). The intention of tiered storage is to configure various types of storage systems and media for different levels of performance, availability, capacity and energy or economics (PACE) capabilities to meet a given set of application service requirements. Other storage mediums such as HDD, SSD, magnetic tape and optical storage devices are also used in tiered storage.
Storage tiering can mean different things to different people. For some it is describing storage or storage systems tied to business, application or information services delivery functional need. Others classify storage tiers by price band or how much the solution costs. For others it’s the size or capacity or functionality. Another way to think of tiering is by where it will be used such as on-line, near-line or off-line (primary, secondary or tertiary). Price bands are a way of categorizing disk storage systems based on price to align with various markets and usage scenarios. For example consumer, small office home office (SOHO) and low-end SMB in a price band of under $5,000 USD, mid to high-end SMB in middle price bands from $50,000 to $100,000 range, and small to large enterprise systems ranging from a few hundred thousand dollars to millions of dollars.
Another method of classification is by high performance active or high-capacity inactive or idle. Storage tiering is also used in the context of different mediums such as high performance solid state devices (SSD) or 15,500 revolution per minute (15.5K RPM) SAS of Fibre Channel hard disk drives (HDD), or slower 7.2K and 10K high-capacity SAS and SATA drives or magnetic tape. Yet another category is internal dedicated, external shared, networked and cloud accessible using different protocols and interfaces. Adding to the confusion are marketing approaches that emphasize functionality as defining a tier in trying to standout and differentiate above competition. In other words, if you can’t beat someone in a given category or classification then just create a new one.
Another dimension of tiered storage is tiered access, meaning the type of storage I/O interface and protocol or access method used for storing and retrieving data. For example, high-speed 8Gb Fibre Channel (8GFC) and 10GbE Fibre Channel over Ethernet (FCoE) versus older and slower 4GFC or low-cost 1Gb Ethernet (1GbE) or high performance 10GbE based iSCSI for shared storage access or serial attached SCSI (SAS) for direct attached storage (DAS) or shared storage between a pair of clustered servers. Additional examples of tiered access include file or NAS based access of storage using network file system (NFS) or Windows-based Common Internet File system (CIFS) file sharing among others.
Different categories of storage systems, also called tiered storage systems, combine various tiered storage mediums with tiered access and tiered data protection. For example, tiered data protection includes local and remote mirroring, in different RAID levels, point-in-time (pit) copies or snapshots and other forms of securing and maintaining data integrity to meet various service level, RTO and RPO requirements. Regardless of the approach or taxonomy, ultimately, tiered servers, tiered hypervisors, tiered networks, tiered storage and tiered data protection are about and need to map back to the business and applications functionality.
There is more to storage tiering which includes movement or migration of data (manually or automatically) across various types of storage devices or systems. For example EMC FAST (Fully Automated Storage Tiering), HDS Dynamic Tiering, IBM Easy Tier (and here), and NetApp Virtual Storage Tier (replaces what was known as Automated Storage Tiering) among others.
Likewise there are different types of storage systems or appliances from primary to secondary as well as for backup and archiving.
Then there are also markets or price bands (cost) for various storage systems solutions to meet different needs.
Needless to say there is plenty more to tiered storage and storage tiering for later conversations.
However for now check out the following related links:
Non Disruptive Updates, Needs vs. Wants (Requirements vs. wish lists)
Tiered Hypervisors and Microsoft Hyper-V (Different types or classes of Hypervisors for various needs)
Tape is still alive, or at least in conversations and discussions (Using different types or tiers of storage)
EMC VMAX 10K, looks like high-end storage systems are still alive (Tiered storage systems)
Storage comments from the field and customers in the trenches (Various perspectives on tools and technology)
Green IT, Green Gap, Tiered Energy and Green Myths (Energy avoidance vs. energy effectiveness and tiering)
Has SSD put Hard Disk Drives (HDD’s) On Endangered Species List? (Tiered storage systems and devices)
Tiered Storage, Systems and Mediums (Storage Tiering and Tiered Storage)
Cloud, virtualization, Storage I/O trends for 2013 and beyond (Industry Trends and Perspectives)
Amazon cloud storage options enhanced with Glacier (Tiered Cloud Storage)
Garbage data in, garbage information out, big data or big garbage? (How much data are your preserving or hoarding?)Saving Money with Green IT: Time To Invest In Information Factories
I/O Virtualization (IOV) and Tiered Storage Access (Tiered storage access)
EMC VFCache respinning SSD and intelligent caching (Storage and SSD tiering including caching
Green and SASy = Energy and Economic, Effective Storage (Tired storage devices)
EMC Evolves Enterprise Data Protection with Enhancements (Tiered data protection)
Inside the Virtual Data Center (Data Center and Technology Tiering)
Airport Parking, Tiered Storage and Latency (Travel and Technology, Cost and Latency)
Tiered Storage Strategies (Comments on Storage Tiering)
Tiered Storage: Excerpt from Cloud and Virtual Data Storage Networking (CRC Press, see more here)
Using SAS and SATA for tiered storage (SAS and SATA Storage Devices)
The Right Storage Option Is Important for Big Data Success (Big Data and Storage)
VMware vSphere v5 and Storage DRS (VMware vSphere and Storage Tiers)
Tiered Communication and Media Venues (Social and Traditional Media for IT)
Tiered Storage Explained
Ok, nuff said (for now).
Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press) and Resilient Storage Networks (Elsevier)
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