Best Ceph Alternatives for Proxmox: High-Availability Shared Storage With Better Usable Space (Erasure Coding, Scale-Out, Node Failure Tolerance)

Best Ceph Alternatives for Proxmox: High-Availability Shared Storage With Better Usable Space (Erasure Coding, Scale-Out, Node Failure Tolerance)

When building a high-availability Proxmox cluster, the biggest question many admins face is simple:


“Is there a shared storage system like Ceph that gives better usable space than 3× replication, supports VM OS disks, and increases failure resilience as we add nodes?”

If you're tired of losing 66% of your storage to Ceph’s replication (3 copies = only 33% usable), you’re not alone. Many teams look for:

Higher usable capacity per disk/OSD
Erasure-coding support that still works for VM OS disks
True high availability
More nodes = more failure tolerance
A system that actually integrates well with Proxmox

So… does such a system exist?
Or is Ceph still the only real option for Proxmox?

Let’s break it down.

Can Ceph Erasure Coding Be Used for VM OS Disks?

Many admins think erasure coding is not suitable for VM disks—but Ceph actually supports erasure coding pools for RBD, which is exactly what Proxmox uses for VM OS disks.

But there are trade-offs

Pros
Much higher usable space.
Data is still fully distributed and fault-tolerant.

Cons
Requires more nodes (usually 5+).
Higher CPU overhead.

Slower write latency compared to replication.

Because erasure-coded pools can’t be used independently, Ceph needs a replicated “metadata” pool + erasure-coded “data” pool, which complicates setup for many beginners.

But yes, Ceph erasure coding works for VM disks and is supported by Proxmox.

So What About Ceph Alternatives That Offer More Usable Space?

Here are the realistic options—with honest pros and cons.

1. LINSTOR (DRBD) – Best Ceph Alternative for Proxmox

LINSTOR + DRBD is the closest real competitor to Ceph and is officially supported by Proxmox.

Key Features

Thin provisioning + snapshots
High availability
Works perfectly for VM OS disks
Easier to manage than Ceph
Can use RAID, ZFS, or LVM under the hood
No need for 3× replication

Limits

Does not offer erasure coding
Fault tolerance depends on replication count (2× or 3×)

Who should use it?

Teams that want:

High performance
Simpler setup
No need for huge multi-node EC clusters

2. Sheepdog (Legacy, Not Recommended)

Sheepdog had:

Erasure coding
Block storage for VMs
Scale-out

But it is abandoned and not recommended in 2025.

3. GlusterFS – Works, But Not Ideal for VM OS Disks

Yes, GlusterFS:

Offers replication and erasure coding
Is scale-out
Works fine with Proxmox (via FUSE or NFS)

But:

Not good for VM OS disks → high latency
Prone to split-brain
Performance is inconsistent

Best for file storage, not VM disk images.

4. MinIO, SeaweedFS, MooseFS – Object/File Storage Only

These systems offer:

Amazing erasure coding
High usable capacity
Multi-node fault tolerance

BUT

They do not support block storage, so they cannot host VM OS disks.

5. Ceph—Still the Most Mature and Best Supported for Proxmox

Love it or hate it, Ceph remains the king because:

Native Proxmox integration
RBD is extremely stable
Supports replication and erasure coding
Scales with nodes
More nodes → higher failure tolerance
Battle-tested in enterprise clusters

And yes:

4 nodes → tolerate 1 node failure

5–6 nodes → tolerate 2 node failures (depending on EC profile)

Ceph is the only solution that ticks all of these boxes today.

Is There Something Better Than Ceph for Proxmox?

If you need:

Feature	Best Choice
High usable capacity (erasure coding)	Ceph EC
Highly available VM OS disks	Ceph or LINSTOR/DRBD
More nodes = more resilience	Ceph
Fully supported by Proxmox	Ceph + LINSTOR
Object storage alternative	MinIO (not for VM disks)

✔ If you need maximum usable storage → Use Ceph Erasure Coding (EC)
✔ If you need simplest HA block storage → Use LINSTOR/DRBD
✔ If you need enterprise-grade scale-out VM storage → Ceph is still the only real option

So yes—Ceph is still the best and most complete shared storage solution for Proxmox, especially when you want erasure coding AND VM OS disk support AND growing fault tolerance as you add nodes.