Modifying Properties of a Namespace

Procedure

1. Choose Resources > Resources > Namespace.
2. Select a desired account from the Account drop-down list in the upper left corner.
3. Click More on the right of a desired namespace and select Modify.

   The Modify Namespace page is displayed.

4. Modify basic information about the namespace.

   Table 1 describes related parameters.

   Table 1 Namespace parameters

   Parameter	Description
   Automatic Update of Atime	Whether to enable the function of automatically updating the atime. Atime indicates the time when the namespace is accessed. After this function is enabled, the system updates the atime based on the value of Update Frequency. NOTE: Enabling Automatic Update of Atime compromises system performance.
   Update Frequency	Atime update frequency. The value can be Hourly or Daily.
   Directory Space Display	Display mode of the space occupied by directories or files in a namespace when the ls -l command is executed. For details, see Table 5.
   Snapshot Directory Visibility	Whether the directory of namespace snapshots is visible. If this parameter is set to Visible, the system displays the .snapshot directory in the namespace.
   Security Style	Security style to be selected based on service requirements, including: Mixed: applies to the scenario where users of CIFS clients (using SMB) and UNIX clients (using NFS/HDFS/DPC) can access and control namespaces. In this style, the permissions are subject to the last permissions set for CIFS clients or UNIX clients. CIFS permissions (NT ACL) and UNIX permissions (UNIX Mode/POSIX ACL/NFSv4 ACL) do not coexist. UNIX: applies to the scenario where UNIX mode bits, POSIX ACLs, or NFSv4 ACLs control user permissions. NOTE: In Mixed style (which supports NT ACLs), if you configure an NT ACL for a file or directory on a Windows client and switch Mixed to UNIX, the NT ACL in Mixed style will become invalid.
   Application Type	The following preset application types are provided for typical applications: GENERAL and PACS. NOTE: The picture archiving and communication system (PACS) is applicable to medical imaging scenarios in hospital imaging departments. For details about the PACS, see the Product Description of the corresponding version. GENERAL is the default value and applies to scenarios except those of PACS. For a namespace with the PACS application type, the semantic-layer distribution algorithm is Simplified mode. In this mode, the number of directory fragments is 1. For a namespace with the GENERAL application type, the semantic-layer distribution algorithm is Balanced mode. In this mode, the number of directory fragments is 8. Directory fragmentation is used to divide a directory metadata object into multiple logical metadata objects. The number of directory fragments refers to the number of copies of metadata objects divided from a single directory. Before a directory is fragmented, subfile data and metadata objects in the directory can belong to only one storage node, leading to concentrated pressure on this node. After the directory is fragmented, subfile data and metadata objects in the directory can evenly belong to multiple storage nodes, improving the namespace concurrency capability. Dividing a directory into multiple fragments is suitable for large directories or directories that contain multiple large files. You can also run the create namespace general command on the CLI to create a namespace with other directory fragments. For details, see the Command Reference of the corresponding version.

5. Modify the space quota and file quantity quota of the namespace.
   Table 2 describes related parameters.

   

   Quotas cannot be configured for the namespace if it is an audit log namespace.

   Table 2 Quota parameters

   Parameter	Description
   Hard Quota	Space hard quota. If the quota is reached, the system immediately forbids writes and reports an alarm. [Value range] 1 KB to 256 PB The value must be greater than those of Soft Quota and Advisory Quota. NOTE: If the used file space reaches the hard quota, the system forbids writes. If you want the system to report an alarm before writes are forbidden, set a soft quota and an advisory quota.
   Soft Quota	Space soft quota. If the quota is reached, the system reports an alarm but still allows writes. If the soft quota grace period elapses or hard quota is reached, the system immediately forbids writes. [Value range] 1 KB to 256 PB The value must be greater than that of Advisory Quota and less than that of Hard Quota.
   Advisory Quota	Space advisory quota. If the quota is reached, the system reports an alarm but still allows writes. [Value range] 1 KB to 256 PB The value must be less than those of Soft Quota and Hard Quota.
   Hard Quota (K)	File quantity hard quota. If the quota is reached, the system immediately forbids writes and reports an alarm. The unit is thousands. [Value range] 1 to 100,000,000 The value must be greater than those of Soft Quota (K) and Advisory Quota (K). NOTE: If the number of files reaches the hard quota, the system forbids file adding. If you want the system to report an alarm before files cannot be added, set a soft quota and an advisory quota.
   Soft Quota (K)	File quantity soft quota. If the quota is reached, the system reports an alarm but still allows writes. If the soft quota grace period elapses or hard quota is reached, the system immediately forbids writes. The unit is thousands. [Value range] 1 to 100,000,000 The value must be greater than that of Advisory Quota (K) and less than that of Hard Quota (K).
   Advisory Quota (K)	File quantity advisory quota. If the quota is reached, the system reports an alarm but still allows writes. [Value range] 1 to 100,000,000 The value must be less than those of Soft Quota (K) and Hard Quota (K).
   Soft Quota Grace Period (Days)	If the used file space or number of files reaches the soft quota, the system generates an alarm but still allows users' writing data or adding new files within this period. If this period elapses, the system immediately forbids writes and new files cannot be added. In addition, an alarm is reported. [Value range] 1 to 4,294,967,294. If this parameter is not specified, the grace period is unlimited. In this case, if the used file space or number of files reaches the soft quota, the system reports an alarm but does not restrict users' writing data or adding new files. NOTE: This parameter can be set only when Soft Quota or Soft Quota (K) is set.

   

   • If the used file space or the number of files in the namespace is less than the hard quota and greater than the soft quota, the system reports an alarm but does not forbid writes and does not delete existing data.
   • If the used file space or the number of files in the namespace is greater than the new space hard quota or file quantity hard quota, the system reports an alarm and forbids writes, but does not delete existing data.

6. Determine whether to enable the DPC function of the namespace. After this function is enabled, the namespace can be mounted to the DPC node.
   

   • After the DPC function is enabled, the maximum and minimum WORM retention periods cannot be set for the object service at the prefix level in the converged interworking scenario.
   • DPC cannot be configured for the namespace if it is an audit log namespace.

7. Set the recycle bin function for the namespace.
   1. Enable Recycle Bin. After the recycle bin function is enabled, the system automatically generates the .recyclebininternal directory in the namespace or a dtree of the namespace when files are deleted from the namespace or dtree for the first time. Files are not deleted immediately. Instead, they are moved to the recycle bin and are deleted only after the retention period expires.
      

      After the recycle bin function is enabled, temporary files generated by applications will also be moved to the recycle bin during file deletion.

   2. Set recycle bin parameters. Table 3 describes related parameters.

      Table 3 Recycle bin parameters

      Parameter	Description
      Retention Period	Duration for retaining files in the recycle bin. If you select Fixed period, you need to set a specific retention period. NOTE: If you select Permanent, files will not be deleted after being moved to the recycle bin. You can go to the .recyclebininternal directory in the namespace to manually delete the files. The retention period takes effect for both the namespace and HDFS recycle bins.
      Recycle Bin Directory Visibility	Whether the recycle bin directory is visible. If this parameter is set to Visible, the system displays the .recyclebininternal directory of the namespace and its dtrees.
      Recycle Bin Operation Permission	Select a user who can operate files in the recycle bin. root: Only user root can operate files in the recycle bin. Common user: The system creates a directory for each user based on the user name and user ID. Users have the permission to operate files in their own directories. User root has the permission to operate all users' directories.

      

      Both the retention period of the recycle bin and the deletion policy of the namespace take effect on the data in the recycle bin. The data is deleted when either of the two policies is met.

8. Configure SmartIndexing. After SmartIndexing is enabled, the system creates indexes for the system metadata and custom metadata fields of files in the namespace. You can search for a list of files through metadata.
   

   This function can be set only when the data pilot service is enabled for the storage pool.

9. Select whether to enable the small-directory performance mode. The small-directory performance mode uses the access nodes as owning nodes of metadata without directory fragmentation, reducing file access I/O forwarding and improving file access performance. To obtain better performance experience, you are advised to:
   • Use DNS domain names for mounting and ensure that the number of clients is greater than that of storage nodes to balance the mounting.
   • Balance the directory creation requests of each client. Do not create directories only on a few clients.
   • Balance the access requests of each directory. Do not bring continuous heavy access pressure to a single directory.
   • Apply the NFS, CIFS, or FTP protocol.
   

   If the preceding conditions are not met, node or directory hotspots may occur, causing performance deterioration. In this case, you are advised not to enable this mode.

10. Determine whether to enable tiered storage.
    1. Enable Tiered Storage.
    2. In the Heterogeneous Device area, select a heterogeneous device that has been added to the storage system. If no heterogeneous device is available, add one by following the instructions provided in Adding a Heterogeneous Device.
    3. In the Target Bucket Name area, enter the name of a bucket on the heterogeneous device.
    4. Determine whether to enable the Retrieve Entire File Upon Direct Read function. When a client initiates a request to read data from a file that has been migrated to a heterogeneous device using SmartTier, the storage system will read the file data from the heterogeneous device by default. After this function is enabled, the storage system will automatically retrieve the entire file during data read from the heterogeneous device and retain the file locally (for one day by default) to improve the performance of continuous reads in a short period of time. However, this will occupy service bandwidth. Therefore, you are advised to enable this function when you have sound network conditions and need to read one file multiple times.
       

       • Ensure that the target bucket is in the account used by the heterogeneous device to provide services.
       • The target bucket name contains 1 to 255 characters.
       • The target bucket name can contain only letters, digits, hyphens (-), underscores (_), and periods (.), and must contain letters or digits.

11. Set audit log items. Enabling Audit Log Items allows the system to record audit logs of operations related to the WORM feature of the namespace by default. To record audit logs of other operations related to the namespace, select the corresponding audit log items.
    The audit log items include Create, Delete, Read, Write, Open, Close, Rename, List folders, Obtain properties, Set properties, Obtain security properties, Set security properties, Obtain extension properties, Set extension properties, and Concatenate files.

    

    • To ensure that the selected audit log items take effect, choose Settings > Data Security > Audit Log to enable the audit log function.
    • If too many audit logs are generated for the audit log items and the audit log collection speed is lower than the audit log writing speed, the temporary buffer space may be insufficient, which may cause service interruption. You are advised to properly configure the items to be audited. For example, configure only Create, Delete, and Write for the namespace.

12. Set a standard SmartCompression policy.
    

    • Standard SmartCompression policies configured on DeviceManager apply only to foreground services. Therefore, the Standard SmartCompression switch refers to the foreground standard SmartCompression switch, the Hot Pool Compression switch refers to the hot pool switch for foreground standard SmartCompression policies, and Compression Algorithm refers to foreground standard SmartCompression algorithms.
    • It is recommended that standard SmartCompression be used for warm and cold data. Enabling this function for production services may cause performance degradation. You are advised not to enable it when high performance is required.
    • Videos, audios, images, encrypted/compressed data, and PDF/XML data cannot be compressed.
    

    • Standard SmartCompression can be enabled only after a license supporting standard SmartCompression is imported.
    • Standard SmartCompression and data encryption are mutually exclusive and cannot be enabled at the same time.
    • When Service Type is set to Intelligent video and image or Media, standard SmartCompression is not supported.
    1. Modify Standard SmartCompression. After this function is enabled, the system compresses data written to the namespace based on the selected compression algorithm.
    2. When the standard SmartCompression function is enabled, the parameters listed in Table 4 can be modified.

       Table 4 Standard SmartCompression parameters

       Parameter	Description
       Hot Pool Compression	Whether to enable hot pool compression. If this function is enabled, data written to the cold, warm, and hot storage pools is compressed. If this function is disabled, only data written to the warm and cold storage pools is compressed.
       Compression Algorithm	Compression algorithms can be Capacity-oriented or Performance-oriented. Capacity-oriented: More capacity space is saved, but service performance may be affected. Performance-oriented: Performance-oriented algorithms provide a lower compression ratio than capacity-oriented algorithms, but have higher performance in an all-SSD storage pool.

13. Click OK.
14. Confirm your operation as prompted.