Cloud Storage Gateway:Manage shares

Create a share

1. Log on to the CSG console.
2. Select the region where the file gateway resides.
3. In the left-side navigation pane, click Gateways. On the Current Gateway Cluster page, click the ID of the file gateway to open the Shares page.
4. In the left-side navigation pane, click Share. On the Shares page, click Create.
5. In the Bucket Settings step, set the parameters and click Next. The following table describes the parameters.

   Parameter	Description
   Cross-region Binding	Yes: You can access a bucket that resides in a different region from the specified gateway. No: You can access only the bucket that resides in the same region as the specified gateway.
   Bucket Region	Select a region where the bucket resides.
   Bucket Name	You can select an existing bucket from the drop-down list. You can also enter a subdirectory of the bucket in the Subdirectory field. The Subdirectory field supports only letters and digits. Note In version 1.0.38 and later, you can map the root directory of a file system to a subdirectory of a bucket. This way, you can isolate file access requests. You can specify an existing subdirectory or a subdirectory that does not exist in the bucket. After you create the share, the specified subdirectory serves as the root directory and stores all related files and directories. Back-to-origin buckets are not supported.
   Encrypt	Valid values: None, Server-side Encryption, and Gateway-side Encryption. If you select Server-side Encryption, you must set the Key ID parameter. You can create a key in the KMS console. For more information, see Create a CMK. After you enable the OSS server-side encryption feature, you can bring your own key (BYOK). The system supports keys that are imported from Key Management Service (KMS). After you enable the OSS server-side encryption feature, the system uses the imported key to encrypt files that are uploaded to OSS from the shared directory. You can call the GetObject API operation to check whether the specified file is encrypted. If the value of the x-oss-server-side-encryption field is KMS and the value of the x-oss-server-side-encryption-key-id field is the key ID in the response header, the file is encrypted. Note Only the users in the whitelist can use this feature. The gateway-side encryption feature is available only for enhanced and advanced gateways. For more information, see Enable gateway encryption. If you create a key in the KMS console, you must select the same region where the specified OSS bucket resides.
   Use SSL to connect Bucket	If you select Yes, you can connect to the OSS bucket over SSL.

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

   Parameter	Description
   Share Name	The name of the NFS or SMB share that you want to create. If you set the Protocol parameter to NFS, the share name also specifies the virtual path of NFS version 4 (NFSv4). The name must be 1 to 32 characters in length, and can contain letters and digits. The name cannot start with a digit.
   Protocol	The name of the protocol that you use to connect to OSS buckets. Valid values: NFS and SMB. The NFS protocol is suitable if you need to access OSS buckets from a Linux operating system. The SMB protocol is suitable if you need to access OSS buckets from a Windows operating system.
   Cache	Select an existing cache disk. Note For a cache disk whose capacity is smaller than 5 TB, 20% of the space is used to store metadata. For a cache disk whose capacity is 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 available cache space is 32 GB. If you create a cache disk of 20 TB, the available cache space is 19 TB.
   User Mapping	Maps an NFS client user to an NFS server user. This parameter is available only when you set Protocol to NFS. none: NFS client users are not mapped to the nobody user on the NFS server. root_squash: restricts the use of root user permissions. NFS clients that use the root identity are mapped to the nobody user on the NFS server. all_squash: restricts all user permissions. The NFS client is mapped to the nobody user on the NFS server regardless of the identity that the client uses. all_anonymous: restricts all user permissions. The NFS client is mapped to the anonymous user on the NFS server regardless of the identity that the client uses.
   Archive	This parameter is available only if you set the Protocol parameter to NFS and the User Mapping parameter to none. If you select Yes, the archive feature is enabled. You can use the archive management tool to archive and restore files in a share. If you select No, the archive feature is disabled. You cannot use the archive management tool to manage files. When you read data from an archived file, the system initiates a request to restore the file. Latency may occur during the restoration, but no error occurs. Note Basic file gateways do not support the archive feature.
   Add to Sync Group	You can enable the express synchronization feature for the share and add the share to a synchronization group. Then, all changes made to the data stored in the associated OSS bucket is synchronized to the on-premises client of the share. After you select the Add to Sync Group check box, the Reverse Sync check box is automatically cleared. Note To enable this feature, create a synchronization group first. Make sure that the synchronization group and the share use the same OSS bucket. For more information about how to create a synchronization group, see Express synchronization. Only Standard, Enhanced, and Performance Optimized gateways support the express synchronization feature. The express synchronization feature is implemented based on Alibaba Cloud Message Service. After you add a share to a sync group, you are charged for Message Service. For more information about pricing, see the "Background information" section of the Express synchronization topic.
   Advanced Settings	After you select the Advanced Settings check box, the Advanced Settings step appears.

7. In the Advanced Settings step, set the required parameters, and then click Next. The following table describes the parameters.

   Parameter	Description
   Mode	Replication Mode: In this mode, two backups are created for all data. One backup is stored in the on-premises cache disk and the other backup is stored in the associated OSS bucket. Cache Mode: In this mode, the backup that is stored in the on-premises cache disk contains only metadata and the user data that is frequently accessed. The backup that is stored in the OSS bucket contains all data.
   Transfer Acceleration	This feature accelerates data transfer across regions by using the public bandwidth of the gateway. Before you use this feature, make sure that the transfer acceleration feature is enabled for the associated OSS bucket.
   Fragmentation Optimization	Specifies whether to optimize the performance for applications that frequently and randomly read and write small amounts of data. Proceed with caution.
   Direct IO Mode	Data is directly read from and written to the cache disk.
   Upload Optimization	If you select Yes, cached data is cleared in real time. You can enable this feature if you want to synchronize only backups to the cloud.
   Reverse Sync	Specifies whether to synchronize metadata stored in the OSS bucket to the on-premises cache disk. This feature is suitable for disaster recovery, data restoration, and data sharing scenarios. Note During a reverse synchronization 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 select 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 causes the amount of fees to increase. If you configure the cache mode for the share and download data, you must set the interval to a value between 3,600 seconds and 36,000 seconds.
   Ignore Deletions	If you select Yes, the data that is deleted from the on-premises cache disk is not deleted from the OSS bucket. The OSS bucket retains all data.
   NFS V4 Optimization	Specifies whether to improve the upload efficiency of NFSv4 files. If you select Yes, you cannot mount an NFSv3 file system on your on-premises host.
   Sync Latency	You can specify a period of time to delay the upload of files that you modified and closed. The Sync Latency feature prevents OSS file fragmentation that is 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. Then, 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	Specifies the scope of files to which the replication mode applies. 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. The rest of the data uses the 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 under the shared root directory. For example, if the actual directory is /mnt/myshare/mydir/ and the mount point 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 If you want to use the data replication feature, the capacity of the cache disk must be 1.1 times larger than the file size that you want to replicate. Specify the cache capacity based on the expected growth of the bucket usage. When you enable the data download feature for the first time, a full scan is triggered. This process may reduce the performance of the gateway. We recommend that you enable the data download feature during off-peak hours and wait for the system to replicate all data. The data download feature 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. Other users can only download data. Data loss may occur if multiple users write data to and read data from the bucket at the same time. Proceed with caution.
   Download Speed Limit	After you enable Data Download, you must set this parameter. The download speed must be in the range of 0 MB/s to 1,280 MB/s. If you set this parameter to 0 MB/s, the download speed is unlimited.
   Reverse Sync Interval	After you enable Data Download, you must 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 that is greater 3600. Otherwise, repeated scans result in frequent OSS API calls. This causes the amount of fees to increase. Reverse synchronization is triggered only when you access the directory. To ensure that the data in other directories can be downloaded and new data can be downloaded in real time, use the the express synchronization feature. For more information, see Express synchronization.

9. In the Confirmation step, confirm your settings and 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 share that you want to configure and click Settings in the Actions column.
2. In the NFS Share Settings dialog box, set the parameters. The following table describes the parameters.

   Parameter	Description
   User Mapping	Maps an NFS client user to an NFS server user. none: NFS client users are not mapped to the nobody user on the NFS server. root_squash: restricts the use of root user permissions. NFS clients that use the root identity are mapped to the nobody user on the NFS server. all_squash: restricts the use of all user permissions. The NFS client is mapped to the nobody user on the NFS server regardless of the identity that the client uses. all_anonymous: restricts the use of all user permissions. The NFS client is mapped to the anonymous user on the NFS server regardless of the identity that the client uses.
   Read/Write Client IPs	The IP address or CIDR block of the client that you allow to read data from and write data to the NFS gateway, for example, 192.168.10.10 or 192.168.0.0/24. You can enter multiple IP addresses or CIDR blocks.
   Read-only Client IPs	The IP address or CIDR block of the client that you allow to only read data from the NFS gateway, for example, 192.168.10.10 or 192.168.0.0/24. You can enter multiple IP addresses or CIDR blocks.
   Write Speed Limit	Specify the maximum write speed. Valid values: 0 to 1280. Unit: MB/s. Default value: 0. The default value 0 indicates that the write speed is unlimited.
   Upload Speed Limit	Specify the maximum upload speed. Valid values: 0 to 1280. Unit: MB/s. Default value: 0. The default value 0 indicates that the upload speed is unlimited. Note When you set the maximum write speed and upload speed, make sure that the maximum upload speed is not 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 that you want to configure and click Settings in the Actions column.
2. In the SMB Share Settings dialog box, set the parameters. The following table describes the parameters.

   Parameter	Description
   Browsable	Specify whether the SMB share can be discovered by network neighbors.
   Read/Write Users	The users who have read and write access to the SMB share.
   Read-only Users	The users who have read-only access to the SMB share. Note If you grant both the read-only and read and write permissions to a user, only the read-only permission takes effect.
   Write Speed Limit	Specify the maximum write speed. Valid values: 0 to 1280. Unit: MB/s. Default value: 0. The default value 0 indicates that the write speed is unlimited.
   Upload Speed Limit	Specify the maximum upload speed. Valid values: 0 to 1280. Unit: MB/s. Default value: 0. The default value 0 indicates that the upload speed is unlimited. Note When you set the maximum write speed and upload speed, make sure that the maximum upload speed is not lower than the maximum write speed.

Other supported operations

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