You can delete older snapshots to free up your space as well as decreasing number of snapshots that may cause performance issues and increasing amount of RAM usage for master node to handle large number of snapshots.
You can delete snapshots manually by delete snapshot API:
Delete snapshot API | Elasticsearch Guide [8.2] | Elastic[
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Also you can use retention configuration of Elasticsearch SLM tool to delete older snapshots taken by SLM, when number of snapshots or age of snapshots exceed your defined threshold:
Create a snapshot | Elasticsearch Guide [8.2] | Elastic[
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and
Create or update snapshot lifecycle policy API | Elasticsearch Guide [8.2] | Elastic[
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These deletions of older snapshots do not affect restore process of newer snapshots. Because, when you delete a snapshot (manually or by SLM retention), only those segments that are kept in that snapshot will be deleted and other segments that are pointed by another snapshots remain. Refer to the Elasticsearch Documentation:
"Each snapshot is also logically independent. When you delete a snapshot, Elasticsearch only deletes the segments used exclusively by that snapshot. Elasticsearch doesn’t delete segments used by other snapshots in the repository."
Reference:
Snapshot and restore | Elasticsearch Guide [8.2] | Elastic[
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