Manage shares

Create a share

1. Log on to the CSG console.
2. Select the region where the file gateway is located.
3. On the Gateway Clusters page, find and click the target file gateway.
4. Click the Share tab, and then click Create.
5. On the Bucket Setting tab, set the following parameters and click Next.

   Parameter	Description
   Cross-Region Binding	Yes: You can access OSS buckets that are not deployed in the same region as the gateway. No: You can only access OSS buckets that are deployed in the same region as the gateway.
   Bucket Endpoint	Select the endpoint of the target bucket.
   Bucket Name	You can select an existing bucket from the drop-down list, or enter a subdirectory of the target bucket in the Path Prefix field. The Path Prefix field supports only letters and digits. Note Beginning with version 1.0.38, you can map the root directory of a file system to a subdirectory of a bucket to allow separate file access between users. You can specify an existing subdirectory or a subdirectory that does not exist in the bucket. After you create the share, the specified subdirectory works as the root directory, and stores all related files and directories.
   Encryption	You can select No Encryption or Server Side Encryption. If you select Server Side Encryption, you must also set the CMK ID parameter. You can log on to the KMS console and create a key. For more information, see Create a CMK. After you enable OSS server-side encryption, you can provide your own key. The system supports keys imported from Key Management Service (KMS). After OSS server-side encryption is enabled, the system automatically uses the imported key to encrypt files uploaded to OSS through the shared directory. You can call the GetObject operation to check whether the specified file has been encrypted. In the response header, if the x-oss-server-side-encryption field value is KMS and the x-oss-server-side-encryption-key-id field value is the key ID, it indicates that the file has been encrypted. Note This feature is available to selected users only. When you create a key in the KMS console, you must select the same region as the target OSS bucket.
   Connect to Bucket Using SSL	If you select Yes, you can connect to the OSS bucket over SSL.

6. On the Basic Information tab, set the following parameters and click Next.

   Parameter	Description
   Share Name	Specify a name for the share. If you set the Protocol parameter to NFS, the share name also specifies the virtual path of Network File System version 4 (NFSv4). The name must be 1 to 32 characters in length and can contain letters and digits. It cannot start with a digit. Note File gateways earlier than V1.0.35 do not allow you to mount a share on an on-premises directory over NFSv3. You must run the showmount -e <IP address of the destination gateway> command to obtain the directory to which the share is mounted.
   Protocol	Select NFS or SMB as needed. The NFS protocol applies to scenarios where you need to access Object Storage Service (OSS) buckets from a Linux operating system. The SMB protocol applies to scenarios where you need to access OSS buckets from a Windows operating system.
   Cache	Select an existing cache disk. Note For a cache disk smaller than 5 TB, 20% of the space is used to store metadata. For a cache disk of 5 TB or larger, 1 TB of the space is used to store metadata. For example, if you create a cache disk of 40 GB, the actual available cache space is 32 GB. If you create a cache disk of 20 TB, the actual available cache space is 19 TB.
   User Mapping	Maps an NFS client user to an NFS server user. This parameter is required only when you set the Protocol parameter to NFS. none: NFS client users are not mapped to "nobody" on the NFS server. root_squash: restricts the permissions of the root user. NFS clients that use the root identity are mapped to "nobody" on the NFS server. all_squash: restricts the permissions of all users. No matter what identity an NFS client uses, the client is always mapped to "nobody" on the NFS server. all_anonymous: restricts the permissions of all users. No matter what identity an NFS client uses, the client is always mapped to "anonymous" on the NFS server.
   Archive	You can enable this feature only if you set Protocol to NFS. If you select Yes, archiving is enabled. Reading an archived file initiates a request to restore the file. The request does not trigger error messages. However, the request increases the latency to read the file. If you select No, archiving is disabled. Reading an archived file initiates a request to restore the file. You must restore the archived file first. Otherwise, an error message appears. Note File gateways of the Basic type do not support the Archive feature.
   Add to Sync Group	For example, assume that you enable the express synchronization feature for the share and add the share to a sync group. Changes of the data stored in the associated OSS bucket will be synchronized to the on-premises CSG agent of the share. If you select the Join Sync Group check box, the Remote Sync check box is automatically cleared. Note To enable this feature, create a sync group first. Make sure that the sync group and the share use the same OSS bucket. For more information, see Express synchronization. Only standard, enhanced, and advanced gateways support the express synchronization feature. The express synchronization feature must work with Alibaba Cloud Message Service. After you add a share to a sync group, you are charged for Message Service. For more information, see the background information in Express synchronization.
   Advanced Settings	If you select Advanced Settings, the Advanced Settings tab appears.

7. On the Advanced Settings tab, set the following parameters, and then click Next.

   Parameter	Description
   Cache Mode	Replication Mode: In this mode, two backups of all data are created. One is stored in the on-premises cache disk and the other is stored in the associated OSS bucket. Cache Mode: In this mode, the backup stored in the on-premises cache disk only contains metadata and user data that is frequently accessed. The backup stored in the OSS bucket contains all data.
   Transfer Acceleration	This feature accelerates the data transfer rate across regions by using the public bandwidth of the gateway. Before you use this feature, make sure that the associated OSS bucket enables this feature.
   Fragmentation Optimization	Specifies whether to optimize the performance for applications that frequently and randomly read and write small amounts of data. You can enable this feature based on your needs.
   Direct IO Mode	Data is directly read from and written to the cache disk.
   Upload Optimization	This feature releases cache in real time. You can enable this feature if you synchronize only backups to the cloud.
   Reverse Sync	Specify whether to synchronize metadata stored in the OSS bucket to the on-premises cache disk. This feature applies to disaster recovery, data restoration, and data sharing scenarios. Note During a remote sync process, the system scans all objects in the bucket. If the number of objects is large, you are charged for calling the OSS API. For more information, see Pricing of OSS. If you have selected the Add to Sync Group check box on the Basic Information tab, this option is unavailable.
   Reverse Sync Interval	If you set Reverse Sync to Yes, you must set the Reverse Sync Interval parameter. Valid values: 15 to 36000. Default value: 36000. Unit: seconds. Note If the bucket contains a large number of objects, we recommend that you set the interval to a value greater than 3,600 seconds. Otherwise, repeated scans result in frequent OSS API calls. This incurs a large amount of fees. If you configure the cache mode for the share and download data, you must set the interval between 3,600 seconds and 36,000 seconds.
   Ignore Deletions	During the data synchronization process, the OSS bucket ignores all delete operations. The backup stored in the OSS bucket contains all data.
   NFS V4 Optimization	This feature improves the efficiency of uploading files when you mount a share on your CSG agent over Network File System version 4 (NFSv4). If you enable this feature, Network File System version 3 (NFSv3) is no longer supported.
   Sync Latency	You can specify a period of time to delay the upload of files that you have modified and closed. The Sync Latency feature prevents OSS file fragmentation caused by frequent on-premises modifications. Default value: 5. Maximum value: 120. Unit: seconds.
   Replication Mode Advanced Settings	If you set Cache Mode to Replication Mode, you can select the Replication Mode Advanced Settings check box. The Replication Mode Advanced Settings tab appears.

8. On the Replication Mode Advanced Settings tab, set the following parameters, and then click Next.

   Parameter	Description
   Configure Directory in Replication Mode	This parameter specifies the files to which the replication mode is applied. If you do not select this check box, the replication mode is applied to all data in the share. After you select the check box, click Add Directory to add directories. The replication mode is applied to the specified directories whereas the rest of the data adopts cache mode. Note If you change the mode of a directory from cache to replication, the files in the directory can be synchronized only when the data replication feature is also enabled. We recommend that you enable data replication. You can specify relative directories in the shared root directory. For example, if the specified directory is /mnt/myshare/mydir/ and the mount target is /mnt/myshare, you can enter /mydir/.
   Data Download	By default, the remote sync and the express synchronization features synchronize the metadata between the OSS bucket and the CSG agent. The data replication feature allows you to replicate all data or data of specific directories to the CSG agent. After you enable Reverse Sync or Express synchronization, you can select Yes to enable Data Download. Note Data replication requires the capacity of the cache disk to be 1.1 times larger than the file size to be replicated. Specify the cache capacity based on the expected growth of the bucket usage. When you enable data replication for the first time, a full scan is triggered. This process may reduce the performance of the gateway. Enable data replication during off-peak hours and wait for the system to replicate all of the data. Data replication allows only one user to write data to the bucket and multiple users to read data from the bucket at the same time. If multiple users access the bucket at the same time over the gateway or OSS bucket, only one user can upload files to the bucket, and other users can only download data. If multiple users access the bucket at the same time over the gateway or OSS bucket, only one user can upload files to the bucket, and other users can only download data.
   Download Speed Limit	After you enable Data Download, set this parameter. The download speed must not be lower than 0 MB/s and not be higher than 1,280 MB/s. If you set this parameter to 0 MB/s, it indicates that the download speed is not limited.
   Reverse Sync Interval	After you enable Data Download, set this parameter. Valid values: 3600 to 36000. Default value: 36000. Unit: seconds. Note If the bucket contains a large number of objects, we recommend that you set the interval to a value greater than 3,600 seconds. Otherwise, repeated scans result in frequent OSS API calls. This incurs a large amount of fees. Remote sync is triggered only when the shared directory is accessed. We recommend that you enable express synchronization. This ensures that existing and incremental data in the shared directory can be synchronized to the CSG agent if no user accesses the directory. For more information, see Express synchronization.

9. Click Next to go to the Summary tab, make sure that the specified information is correct, and then click OK.

Configure an NFS share

If you select the NFS protocol when you create a share, click Settings in the Actions column to configure the NFS share.

1. On the Share page, find the target share, and then click Settings in the Actions column.
2. In the NFS Share Settings dialog box, set the following parameters.
   • User Mapping: Select an NFS identity mapping to map NFS client users to NFS server users.
     • none: NFS client users are not mapped to "nobody" on the NFS server.
     • root_squash: restricts the permissions of the root user. NFS clients that use the root identity are mapped to "nobody" on the NFS server.
     • all_squash: restricts the permissions of all users. No matter what identity an NFS client uses, the client is always mapped to "nobody" on the NFS server.
     • all_anonymous: restricts the permissions of all users. No matter what identity an NFS client uses, the client is always mapped to "anonymous" on the NFS server.
   • Read/Write Clients: Specify IP addresses or CIDR blocks allowed to read and write the NFS share.

     For example, enter 192.168.10.10 or 192.168.0.0/24. You can enter multiple IP addresses or CIDR blocks.

   • Read-only Clients: Specify IP addresses or CIDR blocks that can be used to only read the NFS share.

     For example, enter 192.168.10.10 or 192.168.0.0/24. You can enter multiple IP addresses or CIDR blocks.

   • Write Speed Limit: The maximum write speed is 1,280 MB/s. The default value, 0, indicates that the write rate is not limited.
   • Upload Speed Limit: The maximum upload speed is 1,280 MB/s. The default value, 0, indicates that the upload speed is not limited.
     Note When you customize the maximum write speed and upload speed, make sure that the maximum upload speed is no lower than the maximum write speed.

Configure an SMB share

If you select the SMB protocol when you create a share, you can click Set in the Actions column to configure the SMB share.

1. On the Share page, find the share and click Settings in the Actions column.
2. In the SMB Share Settings dialog box, set the following parameters.
   • Browsable: Specify whether the share can be discovered by Network Neighborhood.
   • Read/write Users: Specify users who can read and write the SMB share.
   • Read-only Users: Specify users who can only read the SMB share.
     Note If you grant a user both the read-only and read and write permissions, only the read-only permission takes effect.
   • Write Speed Limit: The maximum write speed is 1,280 MB/s. The default value, 0, indicates that the write speed is not limited.
   • Upload Speed Limit: The maximum upload speed is 1,280 MB/s. The default value, 0, indicates that the upload speed is not limited.
     Note When you customize the maximum write speed and upload speed, make sure that the maximum upload speed is no lower than the maximum write speed.

Other supported operations

On the Share page, you can also perform the following operations.