Updated on 2023-04-26 GMT+08:00

Creating a Bucket

A bucket is a container that stores objects in OBS. Before you store data in OBS, you need to create a bucket.

An account (including all IAM users under this account) can create a maximum of 100 buckets and parallel file systems. You can use the fine-grained access control of OBS to properly plan and use buckets. For example, you can create folders in a bucket based on object prefixes and use fine-grained permission control to implement permission isolation between departments.


  1. In the navigation pane of OBS Console, choose Object Storage.
  2. In the upper right corner, click Create Bucket. The Create Bucket page is displayed. For details, see Figure 1.

    Figure 1 Creating a bucket

  3. Configure bucket parameters.

    Table 1 Bucket parameters




    Geographic area where a bucket resides. For low latency and faster access, select the region nearest to you. Once the bucket is created, its region cannot be changed.

    Most OBS features are available in all regions, but some are only available for certain regions. Consider the feature availability in each region when you select a region for a bucket. For details, see Function Overview.

    If your ECS needs to access an OBS bucket over the intranet, ensure that the bucket and the ECS are in the same region. For details, see Accessing OBS over an Intranet.

    Bucket Name

    Name of the bucket. A bucket name must be unique across all accounts and regions. Once a bucket is created, its name cannot be changed.

    According to the globally applied DNS naming rules, an OBS bucket name:

    • Must be unique across all accounts and regions. The name of a deleted bucket can be reused for another bucket or a parallel file system at least 30 minutes later after the deletion.
    • Must be 3 to 63 characters long. Only lowercase letters, digits, hyphens (-), and periods (.) are allowed.
    • Cannot start or end with a period (.) or hyphen (-), and cannot contain two consecutive periods (..) or contain a period (.) and a hyphen (-) adjacent to each other.
    • Cannot be formatted as an IP address.

      When you access OBS through HTTPS using virtual hosted-style URLs, if the bucket name contains a period (.), the certificate verification will fail. To work around this issue, you are advised not to use periods (.) in bucket names.

    Data Redundancy Policy

    • Multi-AZ storage: Data is stored in multiple AZs to achieve higher reliability.
    • Single-AZ storage: Data is stored in a single AZ, with lower costs.

    For details about the performance comparison between multi-AZ and single-AZ storage, see Comparison of Storage Classes.

    Once a bucket is created, the data redundancy storage policy cannot be changed, so plan in advance and select the policy that can meet your service needs.

    • Multi-AZ storage is not available for buckets in the Archive storage class.

    Default Storage Class

    Storage classes of a bucket. Different storage classes meet different requirements for storage performance and costs.

    • The Standard storage class is for storing a large number of hot files or small files that are frequently accessed (multiple times per month on average) and require quick retrieval.
    • The Infrequent Access storage class is for storing data that is less frequently accessed (less than 12 times per year on average) and requires quick retrieval.
    • The Archive storage class is for archiving data that is rarely accessed (once a year on average) and has no requirements for quick retrieval.

    For details, see Storage Classes.

    Bucket Policy

    Controls read and write permissions for buckets.

    • Private: No access beyond the bucket ACL settings is granted.
    • Public Read: Anyone can read objects in the bucket.
    • Public Read and Write: Anyone can read, write, or delete objects in the bucket.

    Server-Side Encryption

    By choosing SSE-KMS, you can select the default key in the current region to encrypt the objects you upload to the bucket. If you do not have a default key, OBS automatically creates one the first time you upload an object. You can also choose a custom key for encryption. If no such key is available, click Create KMS Key to create one on the KMS console.

    When server-side encryption is enabled for a bucket, you can configure an object to inherit the bucket's KMS encryption settings when you upload the object to the bucket.


    When you enable write-once-read-many (WORM), you can configure a retention policy for the current bucket. The object version which the retention policy is applied to cannot be deleted within a specified period. You can only enable WORM when you create a bucket. Once enabled for a bucket, WORM cannot be disabled. When you enable WORM, OBS automatically enables versioning for the bucket, and versioning cannot be suspended later for that bucket.

    Direct Reading

    Direct reading allows you to directly download objects from the Archive storage class without restoring them in advance. Direct reading is a billable function. For details, see Product Pricing Details.

    No matter which default storage class you select, you can enable direct reading for your bucket. For example, if you select the Standard storage class and enable direct reading for your bucket, you can directly download objects stored in the Archive storage class from your bucket.

    Enterprise Project

    You can add a bucket to an enterprise project for unified management.

    Create an enterprise project by referring to Creating an Enterprise Project. The default enterprise project is named default.

    On the Enterprise Project Management page, create an enterprise project, and add a user group to the enterprise project. By doing so, users in this user group obtain the permissions on the buckets and objects in the enterprise project.


    Only an enterprise account can configure enterprise projects.

    OBS ReadOnlyAccess and OBS OperateAccess are the fine-grained authorizations of the enterprise project user group in OBS.


    Optional. Tags are used to identify and classify buckets in OBS. Each tag is represented by a key-value pair.

    For more information, see Tags.

  4. Click Create Now.

Related Operations

After the bucket is created, you can change its storage class by performing the following steps:

  1. In the navigation pane of OBS Console, choose Object Storage.
  2. In the bucket list, locate the bucket you want and click Change Storage Class on the right.
  3. Select the desired storage class and click OK.

    • Changing the storage class of a bucket does not change the storage class of existing objects in the bucket.
    • An object inherits the bucket storage class by default, if no other storage class is specified for the object upon its upload. When the bucket storage class is changed, newly uploaded objects inherit the new bucket storage class by default.