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What are Placement Targets ?¶

Placement targets control which Pools are associated with a particular bucket. A bucket’s placement target is selected on creation, and cannot be modified.
Where are they set ? Where to edit them ?
Zonegroup and zones

Placement target details are present in zonegroup and zone. Be default a default placement target is created and used.
Users

RGW Users can also se a default placement for themseleves which will the put a Location constraint on the buckets and then buckets will use that placement target only
LocationConstraint

Passing a particular placement target in LocationConstraint will override above two and use the passed one for bucket.

Ceph dashboard UI allows easy way to set that!
Having said that, in case users dont set this then it will go to:

1. Users’ default placement

2. If that is not found, it will default to zonegroup’s default placement which is always present.

Working of placement targets¶

1. Create a bucket without specifying any placement target and choose a user which has no default placement set

This will create a bucket with default placement target present on zonegroup

2. Create a bucket without specifying any placement target and choose a user which has a default placement set

This will create a bucket with default placement target present in user’s config

3. Create a bucket specifying any placement target and choose a user which has a default placement set

This will create a bucket with placement target selected by user overriding what present on user and zonegroup

For UI¶

- It makes sense to mark it as optional and not required as per above findings

- Also, since this setting has various defaults we can move it to advanced