Capacity Planning
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Ceph Hardware Recommendations for Small Clusters
Ceph hardware recommendations for small clusters: CPU threads and RAM per OSD, PLP SSDs, 10 Gb/s networking, and why N100 boxes fall short.
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Ceph Erasure Coding vs Replication: How to Choose
How erasure coding and replication differ in space amplification, failure tolerance and write cost, with a k+m overhead table and a rule for picking one.
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Ceph Minimum Hardware Requirements: Nodes, CPU, RAM, Network
Ceph needs at least 3 nodes, 4 GiB of RAM per OSD by default, 1 to 6 CPU threads per OSD, 1 TiB drives and a 10 Gb/s network. See how to size each.
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Ceph HEALTH_WARN: Diagnose and Clear Warnings
A triage order for Ceph HEALTH_WARN covering degraded placement groups, nearfull OSDs, missed deep scrubs, autoscaler alerts and monitor clock skew.