How much are your Azure storage costs? How much of that is from Enterprise Vault Disaster Recovery? Azure Site Recovery for your EV archive is costing you.
If you moved Enterprise Vault to Microsoft Azure by lifting and shifting the servers, your vault store partitions probably sit on managed disks. Azure Site Recovery (ASR) likely replicates every one of them to a second region. That is a reasonable way to get to the cloud. It is also one of the most expensive ways to keep an email archive there.
Key Takeaways
- Lifting and shifting from Enterprise Vault to Microsoft Azure leads to unwanted storage expenses.
- Azure storage costs with ASR’s replicated managed disks can take up half of your Azure storage bill.
- Moving archives to Azure Blob Storage or Azure Files can reduce Azure storage costs by 75-90%.
Your Enterprise Vault Disaster Recovery Is Nearly 50% of Your Azure Storage Bill
Bluesource modeled a large EV environment: 360 TiB of archived data on 36 managed disks, all protected by ASR. Storage cost $88,000 a month. Moving the partitions to Azure Blob storage brought that to about $9,000 a month, a 90% reduction. The migration paid for itself in about nine months.
Understanding Azure Storage Costs
Managed disks are built for databases and application servers, not for data that is written once and rarely read. Archive data on managed disks pays for three things it doesn’t need. Put together, the archive cost about $245 per TiB per month.
1. Empty Space
A managed disk bills on its provisioned size. A 16 TiB disk that is half full costs the same as a full one. In our reference environment, partitions averaged 56% full. Nearly half of the disk spend bought nothing.2. Performance That’s Never Used
Archived mail sat on Premium SSD and Standard SSD, at roughly $0.075–0.11 per provisioned GiB a month. Blob cool storage is about $0.015–0.025 per GiB actually stored, making it around 5 times cheaper.3. A Duplicate Copy for Disaster Recovery
This is the big one. ASR replicates at the disk level, so every 16 TiB partition disk has a 16 TiB replica disk in the DR region, at nearly the same price. In our model, ASR replicas were 49% of the total bill: $43,000 of the $88,000 a month.
The Solution: Let the Storage Service Handle DR
Enterprise Vault can write partitions straight to Azure Blob, or to an SMB share on Azure Files. Both bill only for the data you store, at archive-friendly rates. Both replicate on their own, so the partition disks and their ASR replicas can be switched off.
| Option | Monthly cost | Savings | Payback | 5-year net savings |
|---|---|---|---|---|
| Today: managed disks + ASR | $88,175 | |||
| Azure Files Hot GRS, 3-year reserved | $19,282 | 78% | 6.9 months | $3.7M |
| Azure Blob Cool + object replication, 3-year reserved | $8,970 | 90% | 9.2 months | $4.0M |
Reference environment, 360 TiB archived. Azure list prices as of October 2026 with a 20% negotiated discount. Includes transactions, migration costs and professional services.
Comparing Azure Blob and Azure Files
Azure Blob is the cheapest to run. Cool tier with object replication to your DR region costs about $25 per TiB per month, ten times less than today. Priority replication adds a 15-minute RPO SLA.
Azure Files is the easiest to adopt. EV keeps writing to a file system, just a UNC path instead of a drive letter. It costs more to run than Blob but needs less migration effort, so it pays back sooner.
| Azure Blob (EV cloud partition) | Azure Files (SMB partition) | |
|---|---|---|
| Billing basis | Used capacity | Used capacity (standard tiers) |
| Recommended tier | Cool | Standard Hot |
| DR option modeled | LRS + priority object replication to the DR region (15-minute RPO SLA) | GRS to the paired region (no RPO SLA) |
| Modeled rate, list price | $0.0252/GiB-month | $0.0632/GiB-month |
| Reserved capacity | 100 TiB and 1 PiB blocks, 1 or 3 years (Hot, Cool, Archive) | 10 TiB and 100 TiB blocks, 1 or 3 years (Hot, Cool, Premium v1) |
| Transaction cost | Higher per write; modest at archive read rates | Per-operation; SMB creates take several billable ops per file |
| Change to EV | New partition type; EV handles the move between partitions | Partition path moves to a UNC share; closest to today’s model |
The savings hold up when the assumptions change. At list price, savings rise slightly. With fuller disks, Blob still saves 87%. Only removing ASR from the picture changes the story much: savings stay around 80%, but payback stretches to 20 months. The more of your archive ASR protects today, the stronger the case.
Moving from managed discs to Azure Blob storage can reduce spending by 90%.
Before Moving to Azure Blob: Key Considerations
A few things decide how quickly the savings arrive:
- Count files, not terabytes. Migration transactions bill per write, and EV stores several files per archived message. Billions of items add up.
- Get firm services quotes. Azure’s own migration charges are modest. The labor to move the data usually sets the payback period.
- Confirm your DR requirements. Object replication and GRS are asynchronous. Check that the RPO and the DR region meet your policy.
- Check EV compatibility for your version, storage tier and any WORM or retention settings.
- Retire disks as you go. Every month a migrated partition’s disks and replicas stay online is money spent twice.
- Buy reservations last, once you know how much capacity actually landed.
Start with an inventory of your partition disks: SKU, size, how full each one is, and whether ASR protects it. With that and an item count, you can model your own environment in an afternoon. If ASR is protecting archive disks today, there is a good chance most of that spend can go.
Prepare your Migration Plan