I was writing a blog post on Storage Economics last night for ITKE (IT Knowledge Exchange). During some thought  process and writing, I got confused on a sentence I was trying to format. The confusion was between ILM (Information Lifecycle Management) and Storage Tiering. Though I think both the concepts are overlapping, most of the responses I got from twitter were Storage Tiering is a revamped ILM or ILM with lipstick. Twitter search: “ILM, Tiering”.

After thinking about this for the past 24 hours, I am still not sure if I am at the right conclusion.

What is ILM (Information Lifecycle Management):

A process to manage information through out its lifecycle from creation to deletion. Lets look at ILM from a storage perspective.

1) A user or an application creates data and possibly over time that data is modified.
2) The data needs to be stored and possibly be protected through RAID, snaps, clones, replication and backups.
3) The data now needs to be archived as it gets old, and retention policies & laws kick in.
4) The data needs to be search-able and retrievable NOW.
5) Finally the data needs to be deleted.

Though some argue protection (RAID, snaps, clones, replication, backups) are part of ILP: Information Lifecycle Protection and not ILM: Information Lifecycle Management.

Here is a definition of ILM as I found on google: “define: ILM”.

What is Storage Tiering:

A defined pool of Storage within a storage environment that is classified based on either speed, availability, protection levels, access times, SLA’s, frequency of use and possibly cost.

The higher the Storage Tier 0, 1, 2, the higher the cost of management, purchase, availability, speed, protection levels, frequency of use and least access times and outages. The lower the Storage Tier 3, 4, 5, the lower the cost of management, purchase, availability, speed, protection levels, frequency of use and higher access times.

As data gets old or unused, based on workflow, the data moves from higher tiers to lower tiers, could be an automated move, a manual move, a business rules defined move or a policies based move.

Data Protection, Tiering, Archiving, Backup, Retention, Search are all components of Storage Tiering these days. So does this mean, Storage Tiering is merely a subset of ILM.

The Overlap:

I have not heard the word ILM from large vendors in any tech-talk, on any blogs, nor any podcasts these days. So where is ILM or have the vendors given up on the concept of ILM. Is Storage Tiering the new ILM, if that is the case what is the difference.

ILM does include two major components which are data creation and data deletion, but storage tiering does not encompass those, it only preaches moving the data to a lower or higher tier based on availability, backup, archive, retention, search and retrieve features.

So is ILM still alive and if it is, where is it. If it is dead, does it mean we do not have workflows and automation around the other aspects of ILM not included in Storage Tiering. Is Storage Tiering just a marketing buzz and is still uses the underlying concept of ILM.

I am all confused!!!

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Related posts:

1. EMC’s Unified Platform and Storage Tiering on GESTALTIT.COM
2. Storage Economics – Hardware Maintenance – Part 1
3. Basic Network Storage
4. Storage Economics – Hardware Maintenance – Part 2
5. Storage Resource Analysis (SRA): Part 9