Which two steps are performed in preparation for migrating from a self-hosted single-node deployment to a multi-node deployment of Instana?

Migrating from a single-node to a multi-node Instana deployment requires preparing new hosts to function as a cohesive, distributed cluster. A critical preparation step is tuning the operating system on the new hosts by checking and adjusting kernel parameters, such as vm.maxmapcount, which is essential for the stability and performance of components like Elasticsearch. Furthermore, establishing reliable and secure network communication between all nodes is fundamental for a multi-node architecture. This is typically achieved by configuring private IP addresses to ensure the hosts can reach each other for data replication, coordination, and internal API calls.

A. Services on the old host are typically stopped before creating a backup to ensure data consistency for the migration, not started.

B. The official migration procedure involves a backup and restore process, not physically moving disks, which is a high-risk and non-standard method.

D. While Docker is required, kernel tuning and networking are more fundamental preparations that directly address the new complexities of a distributed, multi-node architecture.

1. IBM Instana On-Premises Documentation, "On-premises multi-host on Docker", Section: "Preparing hosts": This section explicitly details the requirement to adjust kernel settings on all hosts. It states, "To avoid issues with Instana and its components, we recommend that you adjust the following settings on all hosts... For Elasticsearch, you need to set vm.maxmapcount to at least 262144." This directly supports answer C.

2. IBM Instana On-Premises Documentation, "On-premises multi-host on Docker", Section: "Prerequisites": This section lists as a primary prerequisite: "All hosts must be able to reach each other over the network." This requirement underpins the need for proper network configuration, such as private IP addresses, for inter-node communication, supporting answer E.

3. IBM Instana On-Premises Documentation, "Backing up and restoring": This document outlines the standard procedure for migration, which involves creating a backup from the source system and restoring it to the target system. This contradicts the method described in option B.