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Example 3: ILM rules and policy for better protection for image files

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You can use the following example rules and policy to ensure that images greater than 1 MB are erasure-coded and that two copies are made of smaller images.

Caution The following ILM rules and policy are only examples. There are many ways to configure ILM rules. Before activating a new policy, simulate it to confirm it will work as intended to protect content from loss.

ILM rule 1 for example 3: Use EC for image files greater than 1 MB

This example ILM rule uses advanced filtering to erasure code all image files greater than 1 MB.

Note Erasure coding is best suited for objects greater than 1 MB. Don't use erasure coding for objects smaller than 200 KB to avoid the overhead of managing very small erasure-coded fragments.
Rule definition Example value

Rule name

EC Image Files > 1 MB

Reference time

Ingest time

Advanced filter for Object size

Object size greater than 1 MB

Advanced filters for Key

  • Ends with .jpg

  • Ends with .png

Placements

Create a 2+1 erasure-coded copy using three sites
ILM rule 1 for example 3: Use EC for image files greater than 1 MB

Because this rule is configured as the first rule in the policy, the erasure-coding placement instruction only applies to .jpg and .png files that are greater than 1 MB.

ILM rule 2 for example 3: Create 2 replicated copies for all remaining image files

This example ILM rule uses advanced filtering to specify that smaller image files be replicated. Because the first rule in the policy has already matched image files greater than 1 MB, this rule applies to image files that are 1 MB or smaller.

Rule definition Example value

Rule name

2 Copies for Image Files

Reference time

Ingest time

Advanced filters for Key

  • Ends with .jpg

  • Ends with .png

Placements

Create 2 replicated copies in two storage pools

ILM policy for example 3: Better protection for image files

This example ILM policy includes three rules:

  • The first rule erasure codes all image files greater than 1 MB.

  • The second rule creates two copies of any remaining image files (that is, images that are 1 MB or smaller).

  • The default rule applies to all remaining objects (that is, any non-image files).

ILM policy for example 3: Better protection for image files