Linux Server / Filesystems, LVM & Recovery
Inspect software RAID state before replacing a Linux disk
A degraded array needs exact member identity and recovery context. Collect kernel RAID status before removing any component.
Environment and inputs: Linux server baseline · Ubuntu 24.04 LTS / RHEL 9-style systems. Use the specified distribution, init system and installed tool; service names, privileges and supported options can differ.
Start with this check
Confirm the host, shell and access role. Replace sample names, paths, domains and interfaces with approved targets. These are diagnostic commands; assess policy and workload impact before making changes.
cat /proc/mdstatRead the result
On Linux MD RAID hosts, this shows visible arrays and resynchronization information. It does not establish disk serial identity or every controller-managed RAID state.
Resolve and verify
Map the array to mdadm detail, physical inventory and storage errors. Follow the approved member-replacement procedure and monitor rebuild progress.
Before changing production
Do not fail or remove a disk by guessed device name or interrupt a rebuild without assessing redundancy and data safety.