Explore the challenges and solutions for managing large-scale data clusters in Kubernetes environments for LLM pre-training in this 26-minute conference talk. Discover how JuiceFS, a distributed POSIX file system designed for cloud, addresses storage performance, access control management, and system stability issues. Learn about the JuiceFS CSI Driver's architecture and new designs, including mount pod mode and sidecar mode for serverless environments, to support complex AI training tasks. Gain practical insights into LLM storage challenges, architectural considerations, and future developments in managing multi-thousand node Kubernetes clusters for large language model pre-training.