Patrick S.

I need assistance safely recovering my Unraid server (Atlantis) using my existing drives before replacing another failing drive. Current configuration: Unraid 7.2.x, dual parity with two 18 TB Seagate parity drives. Disk 1: 14 TB Seagate Exos (ZTM02968), previously missing but now detected after checking connections. Passed an extended SMART test with zero pending, reallocated, or uncorrectable sectors. Disk 4: 8 TB Seagate Archive SMR (Z840R2L9), disabled but physically detected. Has historical ATA errors and 5,005 CRC errors. Disk 10: 8 TB Seagate BarraCuda SMR (ZCT0R53D), active but has 16 pending sectors, 16 offline uncorrectable sectors, and severe I/O latency, often reaching 100% utilization. Both Disk 1 and Disk 4 were already disabled by August 2024, and Unraid has been emulating their contents through dual parity. Disk 1's physical XFS filesystem UUID differs from the current emulated filesystem UUID. Steps completed: Confirmed both parity drives are detected and Unraid reports zero array disk errors. Verified the emulated XFS filesystems mount cleanly. Backed up Unraid's configuration, Disk 1's appdata and 3D printing files, and part of Disk 4's appdata. Disabled Docker and both Mover schedules. Stopped the array cleanly and selected the original Disk 1 for rebuilding onto itself. Current situation: The array is STOPPED. Unraid displays "Replacement disk installed" and warns that starting will initiate a parity-sync and/or data rebuild, overwriting the physical Disk 1. I want to restore normal operation using the existing disks, then replace Disk 10 with a larger CMR drive. Questions: Is it advisable to rebuild Disk 1 onto itself while Disk 4 remains disabled and Disk 10 has known media errors? What is the safest sequence for recovering Disk 1 and Disk 4 without invalidating dual parity? Should I preserve the original disks rather than rebuilding immediately? What precautions should I take before eventually replacing Disk 10? I have attached my latest diagnostics ZIP and would appreciate guidance before starting the rebuild. atlantis-diagnostics-20261112-0615.zip