Using ILM Policy Tags: A Better Option vs One Do-It-All ILM Policy

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ILM Policy tags were a new feature in StorageGRID 11.8. And I think it's a great idea. Instead of controlling ILM via one active do-it-all ILM policy - that can end up with a lot of rules over time - you create ILM Policy Tags which you assign to your buckets.

Note: Screenshots below taken from StorageGRID 11.9.

ILM Policy Tags (4)

To demonstrate, in a lab I've set up 4 x ILM Policy Tags:

(Tag name : Description : Assigned policy : Policy limitations )

  1. Default : Default Policy Tag : Default (1 Copy Per Site) :
  2. EC2+1 @ DC2 (1-site) (FPool) : For FabricPool buckets in DC2 : DC2 FabricPool
  3. EC2+1 @ DC1 (1-site) (FPool) : For FabricPool buckets in DC1 : DC1 FabricPool
  4. App Data (repl. + local prot.) : For application data. It is replicated and has local protection (EC2+1 for objects > 1MB, else 2 copies per site) : App. Data (local & remote protection)
ILM Policy Tags

The Default ILM tag is what a newly created bucket gets given by default. When a bucket is created, a provisioning step is to change the ILM tag on the bucket. Essentially, nothing would be using the default tag, it is just there.

We have two FabricPool tags, because we have 2 StorageGRID sites. FabricPool buckets in DC1 use the DC1 policy. FabricPool buckets in DC2 use the DC2 policy.

For application data, we have EC2+1 local protection (or double data for small objects less than 1MB, where Erasure Coding is not recommended) and site protection too.

ILM Rules (5)

In order to construct these 4 ILM Policy tags, we needed 5 rules:
  •  App Data >= 1MB
  • App Data < 1MB
  • EC2+1 @ DC2
  • EC2+1 @ DC1
  • 1 Copy Per Site (2 sites)
ILM Rules

ILM Policies (4)

We have 4 x Active ILM Policies:
  • Default (1 Copy Per Site)
  • DC1 FabricPool
  • DC2 FabricPool
  • App. Data (local & remote protection)
ILM Policies

IMPORTANT: Bucket options: ILM policy tag

Using ILM Policy Tags, it is important one remembers to set the ILM policy tag when provisioning the bucket. Here's an example application bucket with ILM policy tag assigned.

Bucket Options

Overall, I think it's easier and more intuitive to use the ILM policy tags versus the one do-it-all ILM policy with multiple rules in.

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