Questions regarding incremental snapshot restore

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1

When a snapshot is created in an empty repository, a "full" snapshot will be created, correct?

When a snapshot is created in a repository that contains previous snapshots an "incremental" snapshot will be created containing data modified since the most recent snapshot in the repository, correct?

If I need to restore an entire index do I just restore using the most recent incremental, or is there an iterative process of applying the "full"/"incrementals" ?

If I have a filesystem policy that automatically deletes files that are older than X days and my "full" snapshot becomes that old and gets deleted, I lose my ability to completely restore, correct?

Thank you

2

Correct.

Actually it will contain segments which has been modified since then. New segments can contain old data.

Yes. Just restore latest snapshot and all segments needed to have a full index will be restored.

You will most likely lose your ability to restore even partially. Because the snapshot won't have access to all needed files.
IIRC Snapshot process is able to cleanup non needed remaining old files. Which means segments which are not used anymore.

Hope this helps.