What is Arius?
Arius (from the Greek for immortal) is a command-line tool that archives your files to Azure Blob Storage with client-side encryption and deduplication. It’s designed to support a 3-2-1 backup strategy — keeping data safe offsite at minimal cost using Azure’s Archive tier (~1 EUR/TB/month). Unlike traditional backup tools, Arius leaves small pointer files (.pointer.arius) in your local file system. These pointers maintain full directory visibility in Windows Explorer even when the actual file data lives in Azure — no separate application needed to see what you’ve archived.
Quick Start
Archive your first directory to Azure in minutes
Installation
Install Arius via Docker or as a native binary
CLI Reference
Full reference for the
archive and restore commandsArius Explorer
Windows GUI for browsing your archived repository
Why Arius?
Cost-effective archival
Uses Azure Blob Archive tier at approximately 1 EUR per TB per month — ideal for rarely-accessed data that must be preserved long-term.
Single pane of glass
Pointer files ensure your directory structure is always visible in Windows Explorer without downloading the actual data.
Client-side encryption
All data is compressed and encrypted with AES256 on your machine before it ever leaves your system. Azure never sees plaintext data.
Deduplication
File-level deduplication by default — identical files are stored only once. Optional variable block-size deduplication for even greater savings.
Key Concepts
Pointer Files
When Arius archives a file, it replaces (or accompanies) the local binary with a.pointer.arius file. This pointer contains the SHA256 hash of the original file and metadata needed to restore it. The pointer is tiny — typically a few hundred bytes — and lets you see the complete directory structure without storing the actual data locally.
Blob Archive Tier
Azure Blob Archive tier offers the lowest storage cost but files are offline — they cannot be read directly. To restore data, Azure must first rehydrate the blob to an online tier (Hot or Cool), which takes approximately 15 hours. Arius handles this lifecycle automatically: runrestore once to trigger rehydration, then again ~15 hours later to download.
Deduplication
Arius uses SHA256 hashes to identify files. If two files have identical content, only one copy is stored in Azure. For files larger than a threshold, Arius can also perform variable block-size deduplication within a file (using the--dedup flag), which is useful for large files that change partially over time.
Tools
| Tool | Description |
|---|---|
| Arius CLI | Cross-platform command-line tool for archive and restore operations |
| Arius Docker | Docker container version of the CLI, ideal for scheduled tasks |
| Arius Explorer | Windows WPF application for graphical repository browsing |