Storage Systems and Infrastructure Questions

The physical storage substrate that sits beneath databases and other data-intensive systems: disk and volume management, RAID levels and disk-redundancy trade-offs (capacity vs fault tolerance vs rebuild time), and cloud block and instance-store performance characteristics (IOPS, throughput, latency), including how ephemeral instance-store volumes differ from persistent attached ones. Also covers storage-service tiering: hot, warm, cold, and archival lifecycle policies, the retrieval-cost-versus-latency trade-off, and designing the automation that migrates data between tiers and routes reads across them while meeting latency and cost targets. Covers matching a storage configuration's redundancy and performance profile to a system's durability and throughput requirements. This is distinct from how a database engine implements storage internally (write-ahead logs, page layouts, B-tree versus LSM structures). Aimed at engineers who configure and operate the underlying storage hardware.