Top Mistakes with ScyllaDB: Storage

The blog post discusses the importance of selecting appropriate storage solutions for ScyllaDB deployments, emphasizing that storage is a critical component affecting database performance. It highlights common issues users face, such as performance problems due to suboptimal disk choices, and the need for understanding how databases interact with storage to avoid deployment failures. The post explains how ScyllaDB uses an I/O scheduler and Seastar’s Scheduling Groups to prioritize tasks and manage system resources effectively. It details the evolution of ScyllaDB's I/O scheduler and its current capabilities, which include sophisticated self-throttling and cross-shard capacity sharing. The piece also covers storage-related best practices, including the use of locally attached NVMe SSDs and RAID-0 setups for optimal performance and explains the importance of regular disk evaluations and the use of tools like scylla_io_setup and scylla_fstrim. The author dispels misconceptions about locally attached disks, highlighting their cost-effectiveness and reliability within a replicated database environment.