How to Bulk Change Azure Blob Storage Access Tiers (Hot, Cool, Cold, Archive)
Azure Storage Tiers and the Problem with Managing Them
Section titled "Azure Storage Tiers and the Problem with Managing Them"Azure Blob Storage offers four access tiers: Hot, Cool, Cold, and Archive. Each tier has different storage and retrieval costs. The idea is straightforward: keep frequently accessed data on Hot, move older data to Cool or Cold, and archive rarely needed files to Archive for the lowest per-GB rate.
In practice, managing tiers is not that simple. Azure Portal lets you change tiers one blob at a time. For bulk changes, Microsoft points you to PowerShell scripts, Azure CLI, or lifecycle management policies. If you want to move 500 blobs from Hot to Archive, you are either clicking through the portal for an hour or writing and testing a script.
Lifecycle policies help with automated transitions, but they operate on rules and schedules. They are not designed for the case where you look at a set of files and decide, right now, that these specific blobs need to be on a different tier.
Hot, Cool, Cold, and Archive: The Tiers at a Glance
Section titled "Hot, Cool, Cold, and Archive: The Tiers at a Glance"Azure Blob Storage has four access tiers. The colder the tier, the less you pay to store data and the more you pay, in both money and time, to read it back. Here is the practical comparison.
| Tier | Storage cost | Read cost | Minimum retention | Time to first byte | Best for |
|---|---|---|---|---|---|
| Hot | Highest | Lowest | None | Milliseconds | Data in active use |
| Cool | Lower | Higher | 30 days | Milliseconds | Backups, data read about monthly |
| Cold | Lower still | Higher still | 90 days | Milliseconds | Rarely touched data you still want instantly |
| Archive | Lowest | Highest | 180 days | Hours (rehydration) | Long-term archive and compliance copies |
Two things catch people out:
- Archive is offline. You cannot read an archived blob directly. You first rehydrate it to Hot, Cool, or Cold, which can take up to 15 hours. Plan for that latency before you archive anything you might need quickly.
- Early deletion penalty. If you delete, overwrite, or move a blob out of Cool (30 days), Cold (90 days), or Archive (180 days) before its minimum retention elapses, Azure charges a prorated early deletion fee. Moving a blob to Archive and pulling it back two weeks later is not free.
Moving a warmer blob to a cooler tier is instantaneous. Only the reverse, rehydrating from Archive, takes time.
What Blober Does Differently
Section titled "What Blober Does Differently"Blober is a desktop app that connects to Azure Blob Storage as one of its supported providers. Beyond the usual read, write, list, and delete operations, Blober supports something called mutations for Azure Blob. Mutations let you change properties of existing blobs without transferring any data.
Today, Blober supports two types of Azure mutations:
Storage Tier Changes
Section titled "Storage Tier Changes"Select any number of blobs in the Blober file browser, choose a target tier (Hot, Cool, Cold, or Archive), and run the mutation. Every selected blob gets moved to the new tier. No re-upload, no script, no waiting for a lifecycle policy to kick in.
This is useful when you realize a project is finished and its assets should move to Archive, or when you need to bring archived files back to Cool for a review cycle.
Container Access Level Changes
Section titled "Container Access Level Changes"Azure containers can be set to Private, Blob-level public access, or Container-level public access. Changing access levels usually means navigating to each container in the portal and updating the setting. With Blober, you select the containers you want to modify, pick the access level, and apply.
A Real Example: Post-Production Archival
Section titled "A Real Example: Post-Production Archival"Say you run a media production company. You have a container called project-alpine-2025 with 800 GB of raw footage sitting on Hot storage. The project wrapped three months ago and no one is accessing those files. You are paying Hot rates for storage that should be on Archive.
With Azure CLI, you would write something like:
az storage blob list --container-name project-alpine-2025 --output tsv | \while read line; do az storage blob set-tier --container-name project-alpine-2025 --name "$line" --tier ArchivedoneThis works, but you need to set up authentication, handle pagination for large containers, deal with blobs that are already archived, and test the script before running it on production data.
With Blober, you open your Azure Blob connection, navigate to the container, select all files, choose "Archive" as the target tier, and click run. Done.
More Mutations Coming
Section titled "More Mutations Coming"Tier changes and access levels are the first mutations Blober supports for Azure. The architecture is designed to extend this to other providers and other types of modifications. Future mutations could include things like metadata updates, blob tagging, or replication settings. The goal is to give you the same visual, point-and-click control over blob properties that you already have for transfers.
Setting Up Azure Blob Storage in Blober
Section titled "Setting Up Azure Blob Storage in Blober"Connecting Azure to Blober takes about a minute:
- Open Blober and add a new provider
- Select Azure Blob Storage
- Paste your connection string (the same one you would use with Azure Storage Explorer or the SDK)
- Blober verifies the connection and lists your containers
From there, you can browse blobs, transfer files to or from Azure, and run mutations on existing blobs.
Configuration Options
Section titled "Configuration Options"When using Azure as a destination, Blober lets you configure:
- Storage Tier: Choose which tier new uploads land on (Hot, Cool, Cold, or Archive)
- Write Behavior: Overwrite existing blobs, skip if a blob already exists, or skip only if the blob is archived
These options are set per-workflow, so you can have one workflow that uploads to Hot and another that uploads directly to Archive.
Who Needs This
Section titled "Who Needs This"- DevOps teams managing storage costs across multiple containers and projects
- Media companies archiving completed project assets
- Backup administrators moving cold data to cheaper tiers
- Anyone who has outgrown Azure Portal's one-blob-at-a-time tier management
Common Questions About Azure Blob Tiers
Section titled "Common Questions About Azure Blob Tiers"Does changing a blob's access tier create a new version? No. Changing the tier with the Set Blob Tier operation does not create a new blob version. When versioning is enabled, the operations that create a version are writes: Put Blob, Put Block List, Copy Blob, and Set Blob Metadata. Set Blob Tier is not one of them, so the blob keeps its version ID and only its tier property changes. If you already keep multiple versions, each version holds its own tier, and explicitly tiering a version changes how that version is billed, but no new version is generated.
Can I set the tier per file share or only per storage account? That question is about Azure Files, which is separate from Azure Blob Storage. For Azure Blob, the tier is a property of each blob, so you set it per blob, and Blober changes many at once. For Azure Files, the older standard tiers (transaction optimized, hot, cool) are set per file share rather than per account, but you choose a share's media tier when you create it and cannot move a share between media tiers in place. To change it you create a new share and copy the data over. Blober's bulk tier change applies to Azure Blob blobs.
How long does a tier change take? Moving from a warmer tier to a cooler one, such as Hot to Cool or Cool to Archive, is instantaneous. Bringing a blob back from Archive to an online tier is a rehydration that can take up to 15 hours, depending on the priority you choose.
Can I move blobs to Archive in bulk without PowerShell? Yes. Select the blobs in Blober, choose Archive as the target tier, and run the mutation. No script, no lifecycle policy, no Azure CLI. The same works in reverse to rehydrate selected blobs to Hot, Cool, or Cold.
Will changing tiers re-upload my data? No. A tier change is a property change on the blob in place. Nothing is downloaded or re-uploaded, so there is no egress cost for the change itself.
Get Blober
Section titled "Get Blober"Blober is a one-time purchase. No subscriptions. No transfer fees. No transfer limits.
