Edge Locations
Points of presence close to your servers that eliminate protocol and TCP bottlenecks. Up to 13x faster Proxmox Backup Server transfers over high-latency links. One hostname change, everything else stays the same.
Why Backups Over WAN Are Slow
Proxmox Backup Server backups over high-latency links are significantly slower than available bandwidth allows. Two independent bottlenecks cause this.
Protocol Serialization
PBS uploads chunks one at a time, waiting for a server acknowledgment before sending the next. On a 150 ms round-trip link, this caps throughput at roughly 60 Mbit/s regardless of available bandwidth.
4 MB / 0.150 s = 26.7 MB/s ≈ 213 Mbit/s theoretical maxTCP Congestion Window
A single TCP connection cannot fill a fast, high-latency link. Linux kernel defaults limit a single stream to around 200–250 Mbit/s on a 150 ms path. PBS uses a single TCP connection for the entire backup.
iperf3 ×1: 216 Mbit/s • iperf3 ×8: 1,040 Mbit/sHow Edge Locations Work
An edge location runs two components that address each bottleneck independently.
Your client connects to the nearest edge node
Instead of connecting to Frankfurt, your PBS client connects to an edge location near your server with sub-5 ms latency.
Write accelerator ACKs chunks instantly
The edge node writes each chunk to local NVMe storage and immediately returns success. Your client never waits for a Frankfurt round trip.
Chunks are forwarded asynchronously
Up to 64 parallel uploads forward chunks to the datacenter. Consistency-critical operations (index closes, backup finish) block until all pending chunks are confirmed.
TCP multiplexer saturates the link
8 parallel TCP streams between edge and datacenter, each with its own congestion window. Aggregate throughput scales linearly with stream count.
Data Flow
Your client talks to the nearby edge node at near-LAN speeds. The edge forwards data to the datacenter over parallel TCP streams.
Two Components, Two Bottlenecks
Write Accelerator
A protocol-aware PBS proxy that ACKs chunk uploads instantly by writing to local NVMe storage. Chunks are forwarded to the datacenter with up to 64 parallel uploads. Consistency-critical operations (index closes, backup finish) block until all chunks are confirmed stored. This eliminates the per-chunk round-trip wait that limits PBS throughput.
TCP Multiplexer
Splits the single TCP connection into 8 parallel streams, each with its own kernel congestion window. Traffic is distributed using a framed protocol with round-robin scheduling. The aggregate throughput scales with the number of streams, reaching ~800 Mbit/s through the multiplexer on our test path.
Protocol Correctness
Not all operations can be ACKed instantly. Index closes, finish operations, and appends act as barriers that block until all pending chunk forwards have completed. A backup only reports success when every chunk is confirmed stored in the datacenter. No partial or corrupt backups.
Drop-In Replacement
Change the remote hostname in your Proxmox Backup Server configuration. Credentials, encryption keys, datastore names, and all other settings remain unchanged. If the edge location is unavailable, point back at the direct hostname. Zero lock-in.
Measured Results
Tested on a link between OVH BHS (Beauharnois, Quebec) and Frankfurt. ~150 ms RTT.
| Method | Throughput | vs Direct PBS |
|---|---|---|
| PBS direct | 44–67 Mbit/s | baseline |
| TCP multiplexer only | 80 Mbit/s | ~1.5x |
| iperf3 single stream | 216 Mbit/s | TCP ceiling |
| Write accelerator + TCP mux | 573 Mbit/s | 8–13x |
| iperf3 ×8 streams | 1,040 Mbit/s | link max |
Available Edge Locations
More locations will be added based on demand. Contact us to request one for your region.
Beauharnois, Quebec
North America
bhs1-1.edge.pbs-host.deBest for servers in Canada, US East, and US Central
Hillsboro, Oregon
West America
hil1-1.edge.pbs-host.deBest for servers in US West and US Central
Singapore
Asia
sgp1-1.edge.pbs-host.deBest for servers in Asia and Australia
When Edge Locations Help
Good Fit
- RTT to Frankfurt above 50 ms
- 100 Mbit/s+ upload bandwidth available
- Large VMs or frequent changes
- Servers in North America, Asia, or other distant regions
Won't Help
- Central Europe with sub-20 ms latency
- Upload bandwidth is the actual bottleneck
- Small, infrequent backups where speed doesn't matter
One Hostname Change
No software to install, no agents, no configuration files. Change the remote hostname and you're done.
- Run
ping fra1-ingress.pbs-host.defrom your server. If RTT is above 50 ms, an edge location will help. - Pick the nearest edge location from the list above.
- In the Proxmox Backup Server UI (Datastore → Remotes), change the Host field to the edge hostname. Keep the same port, user, password, and fingerprint.
- Run a backup and check the task log. Transfer rates should be significantly higher.
Built as an Optimization, Not a Dependency
Edge Goes Down
Point your remote back at the direct hostname. Your backups continue at the lower direct speed. No data loss, no reconfiguration beyond the hostname.
Connection Drops Mid-Backup
Unconfirmed chunks are not recorded. The next barrier operation fails, and the client reports the error. No partial or corrupt backup is stored. Retry works normally.
No Data Persists on Edge
Chunks are buffered on NVMe during the backup and forwarded in real time. After the backup completes, no customer data remains on the edge node. Durable storage is only in the main datacenters.
Part of the Full Stack
Edge locations make your backups faster. Combine with other features to make them safer.
Primary Datastore
Your working backup target.
IncludedEdge Locations
Faster transfers over WAN.
IncludedFrequently Asked Questions
ping fra1-ingress.pbs-host.de from your server. If the round-trip time is above 50 ms and you have at least 100 Mbit/s of upload bandwidth, an edge location will improve throughput. If you're in central Europe with sub-20 ms latency, the PBS protocol overhead is negligible and your link bandwidth is the actual constraint.Back Up at Near-LAN Speeds
Edge locations eliminate protocol and TCP bottlenecks for Proxmox Backup Server transfers over high-latency links. Up to 13x faster. No extra cost. One hostname change.
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