---
title: "Microsoft Azure Blob Storage"
description: "Rclone docs for Microsoft Azure Blob Storage"
---

# {{< icon "fab fa-windows" >}} Microsoft Azure Blob Storage

Paths are specified as `remote:container` (or `remote:` for the `lsd`
command.)  You may put subdirectories in too, e.g.
`remote:container/path/to/dir`.

## Configuration

Here is an example of making a Microsoft Azure Blob Storage
configuration.  For a remote called `remote`.  First run:

     rclone config

This will guide you through an interactive setup process:

```
No remotes found, make a new one?
n) New remote
s) Set configuration password
q) Quit config
n/s/q> n
name> remote
Type of storage to configure.
Choose a number from below, or type in your own value
[snip]
XX / Microsoft Azure Blob Storage
   \ "azureblob"
[snip]
Storage> azureblob
Storage Account Name
account> account_name
Storage Account Key
key> base64encodedkey==
Endpoint for the service - leave blank normally.
endpoint> 
Remote config
--------------------
[remote]
account = account_name
key = base64encodedkey==
endpoint = 
--------------------
y) Yes this is OK
e) Edit this remote
d) Delete this remote
y/e/d> y
```

See all containers

    rclone lsd remote:

Make a new container

    rclone mkdir remote:container

List the contents of a container

    rclone ls remote:container

Sync `/home/local/directory` to the remote container, deleting any excess
files in the container.

    rclone sync -i /home/local/directory remote:container

### --fast-list

This remote supports `--fast-list` which allows you to use fewer
transactions in exchange for more memory. See the [rclone
docs](/docs/#fast-list) for more details.

### Modified time

The modified time is stored as metadata on the object with the `mtime`
key.  It is stored using RFC3339 Format time with nanosecond
precision.  The metadata is supplied during directory listings so
there is no overhead to using it.

### Performance

When uploading large files, increasing the value of
`--azureblob-upload-concurrency` will increase performance at the cost
of using more memory. The default of 16 is set quite conservatively to
use less memory. It maybe be necessary raise it to 64 or higher to
fully utilize a 1 GBit/s link with a single file transfer.

### Restricted filename characters

In addition to the [default restricted characters set](/overview/#restricted-characters)
the following characters are also replaced:

| Character | Value | Replacement |
| --------- |:-----:|:-----------:|
| /         | 0x2F  | ／           |
| \         | 0x5C  | ＼           |

File names can also not end with the following characters.
These only get replaced if they are the last character in the name:

| Character | Value | Replacement |
| --------- |:-----:|:-----------:|
| .         | 0x2E  | ．          |

Invalid UTF-8 bytes will also be [replaced](/overview/#invalid-utf8),
as they can't be used in JSON strings.

### Hashes

MD5 hashes are stored with blobs.  However blobs that were uploaded in
chunks only have an MD5 if the source remote was capable of MD5
hashes, e.g. the local disk.

### Authenticating with Azure Blob Storage

Rclone has 3 ways of authenticating with Azure Blob Storage:

#### Account and Key

This is the most straight forward and least flexible way.  Just fill
in the `account` and `key` lines and leave the rest blank.

#### SAS URL

This can be an account level SAS URL or container level SAS URL.

To use it leave `account`, `key` blank and fill in `sas_url`.

An account level SAS URL or container level SAS URL can be obtained
from the Azure portal or the Azure Storage Explorer.  To get a
container level SAS URL right click on a container in the Azure Blob
explorer in the Azure portal.

If you use a container level SAS URL, rclone operations are permitted
only on a particular container, e.g.

    rclone ls azureblob:container

You can also list the single container from the root. This will only
show the container specified by the SAS URL.

    $ rclone lsd azureblob:
    container/

Note that you can't see or access any other containers - this will
fail

    rclone ls azureblob:othercontainer

Container level SAS URLs are useful for temporarily allowing third
parties access to a single container or putting credentials into an
untrusted environment such as a CI build server.

{{< rem autogenerated options start" - DO NOT EDIT - instead edit fs.RegInfo in backend/azureblob/azureblob.go then run make backenddocs" >}}
### Standard options

Here are the Standard options specific to azureblob (Microsoft Azure Blob Storage).

#### --azureblob-account

Storage Account Name.

Leave blank to use SAS URL or Emulator.

Properties:

- Config:      account
- Env Var:     RCLONE_AZUREBLOB_ACCOUNT
- Type:        string
- Required:    false

#### --azureblob-service-principal-file

Path to file containing credentials for use with a service principal.

Leave blank normally. Needed only if you want to use a service principal instead of interactive login.

    $ az ad sp create-for-rbac --name "<name>" \
      --role "Storage Blob Data Owner" \
      --scopes "/subscriptions/<subscription>/resourceGroups/<resource-group>/providers/Microsoft.Storage/storageAccounts/<storage-account>/blobServices/default/containers/<container>" \
      > azure-principal.json

See ["Create an Azure service principal"](https://docs.microsoft.com/en-us/cli/azure/create-an-azure-service-principal-azure-cli) and ["Assign an Azure role for access to blob data"](https://docs.microsoft.com/en-us/azure/storage/common/storage-auth-aad-rbac-cli) pages for more details.


Properties:

- Config:      service_principal_file
- Env Var:     RCLONE_AZUREBLOB_SERVICE_PRINCIPAL_FILE
- Type:        string
- Required:    false

#### --azureblob-key

Storage Account Key.

Leave blank to use SAS URL or Emulator.

Properties:

- Config:      key
- Env Var:     RCLONE_AZUREBLOB_KEY
- Type:        string
- Required:    false

#### --azureblob-sas-url

SAS URL for container level access only.

Leave blank if using account/key or Emulator.

Properties:

- Config:      sas_url
- Env Var:     RCLONE_AZUREBLOB_SAS_URL
- Type:        string
- Required:    false

#### --azureblob-use-msi

Use a managed service identity to authenticate (only works in Azure).

When true, use a [managed service identity](https://docs.microsoft.com/en-us/azure/active-directory/managed-identities-azure-resources/)
to authenticate to Azure Storage instead of a SAS token or account key.

If the VM(SS) on which this program is running has a system-assigned identity, it will
be used by default. If the resource has no system-assigned but exactly one user-assigned identity,
the user-assigned identity will be used by default. If the resource has multiple user-assigned
identities, the identity to use must be explicitly specified using exactly one of the msi_object_id,
msi_client_id, or msi_mi_res_id parameters.

Properties:

- Config:      use_msi
- Env Var:     RCLONE_AZUREBLOB_USE_MSI
- Type:        bool
- Default:     false

#### --azureblob-use-emulator

Uses local storage emulator if provided as 'true'.

Leave blank if using real azure storage endpoint.

Properties:

- Config:      use_emulator
- Env Var:     RCLONE_AZUREBLOB_USE_EMULATOR
- Type:        bool
- Default:     false

### Advanced options

Here are the Advanced options specific to azureblob (Microsoft Azure Blob Storage).

#### --azureblob-msi-object-id

Object ID of the user-assigned MSI to use, if any.

Leave blank if msi_client_id or msi_mi_res_id specified.

Properties:

- Config:      msi_object_id
- Env Var:     RCLONE_AZUREBLOB_MSI_OBJECT_ID
- Type:        string
- Required:    false

#### --azureblob-msi-client-id

Object ID of the user-assigned MSI to use, if any.

Leave blank if msi_object_id or msi_mi_res_id specified.

Properties:

- Config:      msi_client_id
- Env Var:     RCLONE_AZUREBLOB_MSI_CLIENT_ID
- Type:        string
- Required:    false

#### --azureblob-msi-mi-res-id

Azure resource ID of the user-assigned MSI to use, if any.

Leave blank if msi_client_id or msi_object_id specified.

Properties:

- Config:      msi_mi_res_id
- Env Var:     RCLONE_AZUREBLOB_MSI_MI_RES_ID
- Type:        string
- Required:    false

#### --azureblob-endpoint

Endpoint for the service.

Leave blank normally.

Properties:

- Config:      endpoint
- Env Var:     RCLONE_AZUREBLOB_ENDPOINT
- Type:        string
- Required:    false

#### --azureblob-upload-cutoff

Cutoff for switching to chunked upload (<= 256 MiB) (deprecated).

Properties:

- Config:      upload_cutoff
- Env Var:     RCLONE_AZUREBLOB_UPLOAD_CUTOFF
- Type:        string
- Required:    false

#### --azureblob-chunk-size

Upload chunk size.

Note that this is stored in memory and there may be up to
"--transfers" * "--azureblob-upload-concurrency" chunks stored at once
in memory.

Properties:

- Config:      chunk_size
- Env Var:     RCLONE_AZUREBLOB_CHUNK_SIZE
- Type:        SizeSuffix
- Default:     4Mi

#### --azureblob-upload-concurrency

Concurrency for multipart uploads.

This is the number of chunks of the same file that are uploaded
concurrently.

If you are uploading small numbers of large files over high-speed
links and these uploads do not fully utilize your bandwidth, then
increasing this may help to speed up the transfers.

In tests, upload speed increases almost linearly with upload
concurrency. For example to fill a gigabit pipe it may be necessary to
raise this to 64. Note that this will use more memory.

Note that chunks are stored in memory and there may be up to
"--transfers" * "--azureblob-upload-concurrency" chunks stored at once
in memory.

Properties:

- Config:      upload_concurrency
- Env Var:     RCLONE_AZUREBLOB_UPLOAD_CONCURRENCY
- Type:        int
- Default:     16

#### --azureblob-list-chunk

Size of blob list.

This sets the number of blobs requested in each listing chunk. Default
is the maximum, 5000. "List blobs" requests are permitted 2 minutes
per megabyte to complete. If an operation is taking longer than 2
minutes per megabyte on average, it will time out (
[source](https://docs.microsoft.com/en-us/rest/api/storageservices/setting-timeouts-for-blob-service-operations#exceptions-to-default-timeout-interval)
). This can be used to limit the number of blobs items to return, to
avoid the time out.

Properties:

- Config:      list_chunk
- Env Var:     RCLONE_AZUREBLOB_LIST_CHUNK
- Type:        int
- Default:     5000

#### --azureblob-access-tier

Access tier of blob: hot, cool or archive.

Archived blobs can be restored by setting access tier to hot or
cool. Leave blank if you intend to use default access tier, which is
set at account level

If there is no "access tier" specified, rclone doesn't apply any tier.
rclone performs "Set Tier" operation on blobs while uploading, if objects
are not modified, specifying "access tier" to new one will have no effect.
If blobs are in "archive tier" at remote, trying to perform data transfer
operations from remote will not be allowed. User should first restore by
tiering blob to "Hot" or "Cool".

Properties:

- Config:      access_tier
- Env Var:     RCLONE_AZUREBLOB_ACCESS_TIER
- Type:        string
- Required:    false

#### --azureblob-archive-tier-delete

Delete archive tier blobs before overwriting.

Archive tier blobs cannot be updated. So without this flag, if you
attempt to update an archive tier blob, then rclone will produce the
error:

    can't update archive tier blob without --azureblob-archive-tier-delete

With this flag set then before rclone attempts to overwrite an archive
tier blob, it will delete the existing blob before uploading its
replacement.  This has the potential for data loss if the upload fails
(unlike updating a normal blob) and also may cost more since deleting
archive tier blobs early may be chargable.


Properties:

- Config:      archive_tier_delete
- Env Var:     RCLONE_AZUREBLOB_ARCHIVE_TIER_DELETE
- Type:        bool
- Default:     false

#### --azureblob-disable-checksum

Don't store MD5 checksum with object metadata.

Normally rclone will calculate the MD5 checksum of the input before
uploading it so it can add it to metadata on the object. This is great
for data integrity checking but can cause long delays for large files
to start uploading.

Properties:

- Config:      disable_checksum
- Env Var:     RCLONE_AZUREBLOB_DISABLE_CHECKSUM
- Type:        bool
- Default:     false

#### --azureblob-memory-pool-flush-time

How often internal memory buffer pools will be flushed.

Uploads which requires additional buffers (f.e multipart) will use memory pool for allocations.
This option controls how often unused buffers will be removed from the pool.

Properties:

- Config:      memory_pool_flush_time
- Env Var:     RCLONE_AZUREBLOB_MEMORY_POOL_FLUSH_TIME
- Type:        Duration
- Default:     1m0s

#### --azureblob-memory-pool-use-mmap

Whether to use mmap buffers in internal memory pool.

Properties:

- Config:      memory_pool_use_mmap
- Env Var:     RCLONE_AZUREBLOB_MEMORY_POOL_USE_MMAP
- Type:        bool
- Default:     false

#### --azureblob-encoding

The encoding for the backend.

See the [encoding section in the overview](/overview/#encoding) for more info.

Properties:

- Config:      encoding
- Env Var:     RCLONE_AZUREBLOB_ENCODING
- Type:        MultiEncoder
- Default:     Slash,BackSlash,Del,Ctl,RightPeriod,InvalidUtf8

#### --azureblob-public-access

Public access level of a container: blob or container.

Properties:

- Config:      public_access
- Env Var:     RCLONE_AZUREBLOB_PUBLIC_ACCESS
- Type:        string
- Required:    false
- Examples:
    - ""
        - The container and its blobs can be accessed only with an authorized request.
        - It's a default value.
    - "blob"
        - Blob data within this container can be read via anonymous request.
    - "container"
        - Allow full public read access for container and blob data.

#### --azureblob-no-head-object

If set, do not do HEAD before GET when getting objects.

Properties:

- Config:      no_head_object
- Env Var:     RCLONE_AZUREBLOB_NO_HEAD_OBJECT
- Type:        bool
- Default:     false

{{< rem autogenerated options stop >}}

## Limitations

MD5 sums are only uploaded with chunked files if the source has an MD5
sum.  This will always be the case for a local to azure copy.

`rclone about` is not supported by the Microsoft Azure Blob storage backend. Backends without
this capability cannot determine free space for an rclone mount or
use policy `mfs` (most free space) as a member of an rclone union
remote.

See [List of backends that do not support rclone about](https://rclone.org/overview/#optional-features) and [rclone about](https://rclone.org/commands/rclone_about/)

## Azure Storage Emulator Support

You can run rclone with storage emulator (usually _azurite_).

To do this, just set up a new remote with `rclone config` following instructions described in introduction and set `use_emulator` config as `true`. You do not need to provide default account name neither an account key.

Also, if you want to access a storage emulator instance running on a different machine, you can override _Endpoint_ parameter in advanced settings, setting it to `http(s)://<host>:<port>/devstoreaccount1` (e.g. `http://10.254.2.5:10000/devstoreaccount1`).
