# Instance Creation Users may click on the "Create Instance" button and choose the configuration they want to create for the message queue instance. The current message storage is reserved for 3 days and does not support dynamic expansion. Please choose and reserve storage space according to actual business needs. ## Package Types Supports Enterprise and Testing versions: * Enterprise: specifications can be chosen as needed, suitable for different business scenarios. * Testing: preferential pricing, suitable for testing and experience scenes. Note: The test version does not guarantee the stability of instances and data, it is recommended to use only in testing scenarios. ## Instance Specifications The enterprise version supports different gradient specifications, for specific specifications and calculation methods please see [Performance Indicators](/docs/rocketmq/capacity). ## Message Storage Users can set storage volume according to business volume. The default longest message storage time is 3 days. If customization is needed, it can be configured in more settings. Message storage volume supports [Online Expansion](/docs/rocketmq/guide/instance/storage). ## Network Mode Supports both internal and external network modes: * Internal Network: only supports the same VPC or network environment that connects with this VPC instance. * External Network: supports both external and internal network access ways, after creation provides internal and external network addresses, users can use as needed. Note: An already created internal network instance cannot be upgraded to an external network instance, please choose according to the business scenario. ## More Settings Users can adjust some default configurations as needed. * Maximum message retention time: supports customization in the 3~10 day range, if altered, please adjust the message storage size as needed. * Maximum range for custom delay: UrocketMQ provides customized delay messages, the maximum delay range is the longest retention time in days minus one.