McGarrah Technical Blog

Homelab Storage Economics: Ceph vs Single Drive Costs

5 min read

After building and running a Ceph cluster for my homelab, I’ve gained valuable insights into the real-world economics of distributed storage versus traditional single-drive solutions. This analysis breaks down the actual costs per GB across different storage strategies in my setup.

My Current Storage Architecture

My homelab storage consists of three distinct tiers:

Each tier serves different purposes and has dramatically different cost profiles when you factor in redundancy and usable capacity.

Ceph Cluster Economics

The Drive Acquisition Story

Building a 15-drive Ceph cluster happened in phases, with costs varying significantly based on timing and sourcing:

Early Drives (Costco Special)

Later Drives (Amazon/Seagate Sales)

Most Recent Drive

Ceph Storage Math

Raw Capacity: 15 × 5TB = 75TB Total Investment: ~$1,500 (averaging $100/drive) Raw Cost per TB: $20.00/TB

With 3/2 Erasure Coding:

Ceph Advantages Beyond Cost

Backup Storage Economics

Drive Model Purchase Date Cost Cost/TB Current Usage
20TB Avolusion PRO-X 20TB June 16, 2024 $219.99 $11.00/TB ZFS volume for CephFS backups
28TB Seagate Expansion 28TB (STKP28000400) November 21, 2025 $289.99 $10.36/TB Planned as primary backup

Backup Strategy and Efficiency

The backup drives reveal something fascinating about my Ceph cluster’s real-world efficiency. That 20TB drive currently holds complete rsync backups of my entire 50TB usable Ceph capacity, which tells me I’m getting compression ratios of 2.5:1 or better. This isn’t just theoretical - it’s actual data from VMs, containers, and file storage that compresses remarkably well due to similar base images and redundant content.

My plan is to promote the new 28TB drive to primary backup duty while relocating the 20TB drive for off-site backup rotation. This gives me both local and remote backup coverage at an average cost of $10.68/TB - less than half the cost of the Ceph storage, but without any of the redundancy or performance benefits. It’s the perfect complement to the distributed storage: cheap, simple, and effective for disaster recovery scenarios.

Cost Comparison Analysis

Storage Type Raw Cost/TB Usable Cost/TB Redundancy Performance
Ceph Cluster $20.00 $30.00 Built-in (3/2) High (15 drives)
20TB Backup $11.00 $11.00 None Single drive
28TB Backup $10.36 $10.36 None Single drive

The Redundancy Tax

Ceph’s redundancy comes at a 50% capacity penalty, effectively doubling the cost per usable TB. However, this “tax” provides:

The Redundancy Tax vs Backup Value

The backup drives demonstrate why having multiple storage tiers makes sense. While Ceph’s redundancy comes at a 50% capacity penalty, the backup drives show the true efficiency of the cluster - 50TB of usable data compresses well enough that a 20TB drive can hold complete backups. This compression comes from:

Real-World Storage Costs

Total Storage Investment

Operational Considerations

Power Consumption:

Maintenance:

Lessons Learned

1. Timing Matters for Drive Purchases

The $89 Costco drives versus $110+ regular pricing shows a 24% cost difference. Patience and deal hunting significantly impact total cluster cost.

2. Redundancy Has Real Costs

Ceph’s 3/2 erasure coding provides excellent protection but at a 50% capacity penalty. For homelab use, this trade-off provides peace of mind worth the cost.

3. Backup Drives Provide Excellent Value

Large external drives offer the best $/TB ratio and serve as an excellent complement to distributed storage for backup purposes.

4. Compression Is Your Friend

50TB of Ceph data fitting on a 20TB backup drive demonstrates the value of compression and deduplication in real-world scenarios.

Future Storage Strategy

Short Term

Long Term

The Real Story Behind the Numbers

Look, I’ll be honest - when I started building this Ceph cluster, I wasn’t thinking about cost per TB. I was thinking “this is cool distributed storage technology” and “I want to learn how this works.” The economics came later when my wife asked why I needed another 5TB drive.

Turns out the math is actually pretty interesting. Yes, Ceph costs me 3x more per usable TB than just buying big external drives. But here’s the thing - when one of those 5TB drives dies (and they will), I don’t even notice. The cluster just keeps running. Compare that to the heart attack I’d have if my single 28TB backup drive failed.

The $89 Costco drives were a steal, and I kick myself for not buying more when they were available. But even at $110 each, building this cluster has been worth it for the learning experience alone. Plus, there’s something deeply satisfying about having 15 drives working together as one big storage pool.

The backup drives? They’re the unsung heroes of this setup. That 20TB drive backing up my entire 50TB Ceph cluster shows just how well compression and deduplication work in the real world. It’s like having a safety net that costs $11/TB.

Bottom Line: If you’re just looking for cheap storage, buy the biggest external drive you can afford. But if you want to learn about distributed systems, have some redundancy, and don’t mind paying the “education tax,” Ceph is pretty amazing. Just don’t tell my wife how much those drives actually cost.

The real lesson here? Different storage serves different purposes. Sometimes you pay for convenience, sometimes for reliability, and sometimes just for the fun of learning something new. In my homelab, all three have their place.

Tags: ceph, storage, costs, homelab, economics, backup
Categories: homelab, storage