1. Insufficient memory: The advanced part of the Grain Mall needs to handle a lot of data and requests, and run multiple applications and services at the same time, including databases and caches, which consumes a lot of memory resources. 8GB of memory can't meet these requirements, which leads to problems such as slow application running or memory leakage.

2. Insufficient computing resources: The advanced part of Grains Mall needs to deal with complex business logic and computing tasks, such as processing orders and calculating coupons. These tasks need to consume a lot of computing resources, including CPU and GPU. 2GB cloud server can't provide enough computing resources, which leads to problems such as long application response time or timeout.

3. Insufficient network bandwidth: The advanced part of Grains Mall needs frequent data interaction and transmission with users. If the network bandwidth is insufficient, it will lead to problems such as slow data transmission speed and long loading time, which will affect the user experience and business development.