When can I enable the lifecycle management feature?

If the files in a General-purpose NAS file system are accessed less than twice a month, we recommend that you enable the lifecycle management feature. After you enable the feature, the files that meet a specified lifecycle policy are automatically dumped to an Infrequent Access (IA) storage medium. This helps reduce storage costs.

Why am I unable to enable the lifecycle management feature for my file system?

If your General-purpose NAS file system was created before June 1, 2020, you cannot enable the lifecycle management feature or configure lifecycle policies for the file system. The lifecycle management feature is unavailable for file systems for which the data encryption feature is enabled. If you want to enable the lifecycle management feature for file systems that are created before June 2020, submit a ticket.

How do I configure lifecycle policies?

To configure lifecycle policies, you can use the NAS console or OpenAPI Explorer. For more information, see Manage a lifecycle policy and API reference for lifecycle policies.

Which files can be dumped to an IA storage medium?

A file that meets the following conditions can be dumped to an IA storage medium:
  • A lifecycle policy is configured for the directory in which the file is stored.
  • The size of the file is at least 64 KB.
  • The file is not accessed during the period of time that is specified in the lifecycle policy.
    When you create a lifecycle policy, you can configure a rule to dump the files that are not accessed in the previous 14 days, 30 days, 60 days, or 90 days to an IA storage medium. The lifecycle management feature checks whether a file is infrequently accessed based on the atime parameter, which specifies the time when the file was last accessed.
    • The following operations update the atime of a file:
      • Read data from the file.
      • Write data to the file.
    • The following operations do not update the atime of a file:
      • Rename the file.
      • Modify the user, group, mode, or other attributes of the file.

What happens if I configure multiple lifecycle policies for a single directory?

If the files in the directory meet a rule in one of the lifecycle policies, the files are dumped to an IA storage medium.

What happens if I configure two different lifecycle policies for a directory and its subdirectory?

The files in the subdirectory are dumped to an IA storage medium based on both policies.

For example, a policy whose atime threshold is 60 days is configured for a directory and a policy whose atime threshold is 14 days is configured for the subdirectory. In this case, the files in the subdirectory that are not accessed in the previous14 days are dumped to an IA storage medium. The files in the IA storage medium are skipped when the lifecycle management feature checks for infrequently accessed files based on the policy of the parent directory.

Is a lifecycle policy valid for all data in the specified directory?

Yes, the consumption details of reserved instances are refreshed every hour. If the file data in the directory meets the lifecycle policy, the data is automatically dumped to the IA storage medium.

How long does a file that matches a lifecycle policy require to be dumped to an IA storage medium?

If the lifecycle management feature is enabled, a file that meets a specified lifecycle policy is dumped to an IA storage medium in 2 to 24 hours. The time that is required to dump the file to an IA storage medium varies based on the storage usage of the file system and the size of the file. Subsequent file dumps are performed at a specific point in time every week.

What happens if I rename a directory for which a lifecycle policy is configured?

If you rename a directory for which you configure a lifecycle policy, the policy no longer takes effect on the files in the directory. The files that are dumped to an IA storage medium remain in the IA storage medium.

If you configure a lifecycle policy for the renamed directory, the files in the directory that meet the policy are dumped to an IA storage medium.

What happens if a lifecycle policy is deleted?

The files in the directory for which the policy is configured are no longer dumped to an IA storage medium. The files that are dumped to the IA storage medium remain in the IA storage medium.

Are the files in a directory repeatedly dumped to an IA storage medium if I delete the existing lifecycle policy and then reconfigure a lifecycle policy for the directory?

No, after you reconfigure a lifecycle policy, the lifecycle management feature checks for files that meet the policy. The files in the IA storage medium are skipped during the check. This prevents repeated file dumps.

Are the files in an IA storage medium accessible?

Yes, you can read data from and write data to the files in an IA storage medium the same way you read data from and write data to other files in a file system.

Which files in my file system are stored in an IA storage medium?

You can query the files that are stored in an IA storage medium in the NAS console or by calling API operations. For more information, see View the files stored in an IA storage medium and ListDirectoriesAndFiles.

Is the latency when you read data from and write data to a file in an IA storage medium longer than the latency when you read data from and write data to a file in a Performance NAS or Capacity NAS file system?

It depends. The latency when you read data from a file in an IA storage medium for the first time may be longer than the latency when you read from a file in a NAS Performance or NAS Capacity file system. After the file is read, the latency when you read data from the file is almost the same as the latency when you read data from a file in a Performance NAS or Capacity NAS file system.

The latency when you write data to a file in an IA storage medium is almost the same as the latency when you read data from a file in a Performance NAS or Capacity NAS file system.

How am I charged if my files are dumped to an IA storage medium?

If your files are dumped to an IA storage medium, you are charged based on the billing method of the IA storage medium. For more information, see Billing of IA storage media.

Can cold data that is dumped to an IA storage medium be automatically converted to hot data after the cold data is accessed?

No, after cold data is dumped to an IA storage medium, the cold data is stored in the IA storage medium. If you access cold data in the IA storage medium, you are charged for the read and write traffic of the cold data. For more information, see Billing of IA storage media.

If you must frequently access specific files in the IA storage medium, we recommend that you create a data retrieval task to convert the files from cold data to hot data. For more information, see Create a data retrieval task.

How do I create a data retrieval task to retrieve files from an IA storage medium?

You can create a data retrieval task in the NAS console or by using OpenAPI Explorer. For more information, see Create a data retrieval task and CreateLifecycleRetrieveJob.

Is the read or write performance of a file system affected when a data retrieval task is running?

No, the read or write performance of a file system is not affected. You can read or write data as expected when a data retrieval task is running.

Am I charged for a data retrieval task?

Yes, you are charged for a data retrieval task. When you run a data retrieval task, the system reads data from the specified file. You are charged for reading the file from the associated IA storage medium based on the size of the file. If a data retrieval task is successful, the file is moved to the related General-purpose NAS file system and occupies storage space. In this case, you are charged for the storage space based on the size of the file. For more information, see Billing of IA storage media.

How am I charged when I back up files that are stored in an IA storage medium?

If you use Hybrid Backup Recovery (HBR) to back up files that are stored in an IA storage medium of a General-purpose NAS file system, you are charged for using HBR resources. For more information, see Billing methods and billable items.

During the backup process, HBR reads data from the files. Therefore, you are also charged for the traffic that is generated when HBR accesses the IA storage medium. For more information, see Billing of IA storage media.

How am I charged when I use a security service to scan files in an IA storage medium?

When a security service such as the anti-ransomware service of Security Center scans files in an IA storage medium of a General-purpose NAS file system, the security service reads data from the files. You are charged for the traffic that is generated when you access the IA storage medium. The traffic fees are included into your NAS bills. For more information, see Billing of IA storage media.

Why do I need to use Resource Access Management (RAM) to grant the required permissions when I create a mount target in the classic network?

Because you must authorize NAS to verify the Elastic Compute Service (ECS) instances that access your file systems. To ensure data security of your NAS file system, NAS allows only the ECS instances of your Alibaba Cloud account to access your file systems by using the mount target of the classic network. The file systems and ECS instances must belong to the same Alibaba Cloud account. To verify the ECS instances that access your file systems, you must authorize NAS to obtain the ECS instances of your account in the RAM console.
Notice
  • After you complete the authorization, NAS can call only the DescribeInstances operation. NAS uses the ECS instances only for verification.
  • We recommend that you do not delete or modify the AliyunNASDefaultRole role in RAM. Otherwise, exceptions such as mount failures or file system errors may occur.

Why am I unable to view a file system after I log on to the NAS console as a RAM user that has full access permissions on the file system?

  • Symptom:

    After you log on to the NAS console as a RAM user that has full access permissions on a file system, an error message appears when you go to the File System List page.

  • Cause:

    The permissions on tags are not granted to the RAM user. You must configure the permissions of tag:ListTagKeys.

  • Solution:
    Use a custom policy to grant the RAM user the permissions on the tags of the file system that you want to access. For more information, see Perform access control based on RAM policies.
    {
        "Statement": [
            {
                "Effect": "Allow",
                "Action": "nas:*",
                "Resource": "acs:nas:*:*:filesystem/0ddaf487b2"
            },
            {
                "Effect": "Allow",
                "Action": "nas:CreateMountTarget",
                "Resource": "acs:vpc:*:*:vswitch/*"
            },
            {
                "Effect": "Allow",
                "Action": "cms:Describe*",
                "Resource": "*"
            },
            {
                "Effect": "Allow",
                "Action": "nas:DescribeFileSystems",
                "Resource": "*"
            },
            {
                "Effect": "Allow",
                "Action": "tag:ListTagKeys",
                "Resource": "*"
            }
        ],
        "Version": "1"
    }

How do I obtain an AccessKey pair?

  1. Use an Alibaba Cloud account to log on to the Alibaba Cloud Management Console.
  2. In the upper-right corner of the page, move the pointer over the profile picture and click AccessKey Management.
  3. In the Note dialog box, click Use Current AccessKey Pair or Use AccessKey Pair of RAM User.
    • Create an AccessKey pair for the Alibaba Cloud account.
      1. In the Note dialog box, click Use Current AccessKey Pair.
      2. On the AccessKey Management page, click Create AccessKey.
      3. In the Phone Verification dialog box, enter the verification code in the Verification Code field and click OK.
      4. In the Create AccessKey dialog box, view the AccessKey ID and AccessKey secret.

        You can click Save AccessKey Information to download the AccessKey pair.

    • Create the AccessKey pair of the RAM user.
      1. In the Note dialog box, click Use AccessKey Pair of RAM User.
      2. On the Users page of the RAM console, click Create User.

        Skip this step if you want to create an AccessKey pair for an existing RAM user.

      3. In the left-side navigation pane, choose Identities > Users and find the RAM user.
      4. Click the logon name of the RAM user to go to the details page. In the User AccessKeys section of the Authentication tab, click Create AccessKey.
        Note
        • You can create a maximum of two AccessKey pairs for each RAM user.
        • After you create an AccessKey pair, you cannot view the AccessKey secret in the RAM console. We recommend that you keep the AccessKey secret strictly confidential.
      5. In the Phone Verification dialog box, enter the verification code in the Verification Code field and click OK.
      6. In the Create AccessKey dialog box, view the AccessKey ID and AccessKey secret.

        You can click Download CSV File or Copy to save the AccessKey pair.

How can I use the server-side encryption feature of NAS?

When you create a file system, you can select Service Key or Custom Key in the Data Encryption field of the buy page based on your business requirements. For more information, see Create a General-purpose NAS file system in the NAS console and Create an Extreme NAS file system in the NAS console..

Is the server-side encryption feature available on a file system for which this feature is disabled?

No, you can enable the server-side encryption feature only when you create a file system.

Can I disable the server-side encryption feature on a file system for which this feature is enabled?

No, the server-side encryption feature takes effect immediately after it is enabled. You cannot disable the feature.

Can I change the key that is used to encrypt a file system?

No, when you create a file system, a key is specified to encrypt the file system. The key cannot be changed.

Which data encryption method do I need to select, NAS-managed keys or custom keys?

Both two data encryption methods use Key Management Service (KMS) to host keys and use envelope encryption to prevent unauthorized data access.

If you want to use Bring Your Own Key (BYOK) to meet specific security requirements, you can use custom keys. For other scenarios, we recommend that you use NAS-managed keys.
Notice If a custom key that is used to encrypt a NAS file system is disabled or deleted, the NAS file system cannot be accessed.

If a CMK that is applied to a NAS file system is accidentally disabled or deleted, how can I resume access to the data of the NAS file system?

  • If you disable a CMK, re-enable the CMK.
  • If you have scheduled a task to delete a key, cancel the scheduled task. For more information, see Schedule a key deletion task.
  • If the key material of a BYOK key is deleted, re-upload the original key material. For more information, see Import key material.
  • If a CMK is deleted, the CMK cannot be restored. In this case, the data of the related file system cannot be accessed.

After I enable the server-side encryption feature, do I need to use an application to decrypt data each time I access the data?

No, you do not need to use an application to decrypt data after you enable the server-side encryption feature. Data is automatically encrypted and decrypted by NAS. You do not need to perform these operations by using an application.

Is the performance of a file system affected after the server-side encryption feature is enabled for the file system?

Yes, the performance of a file system is affected. After the server-side encryption feature is enabled for a file system, NAS encrypts data that is written to the file system. When you read data from the file system, the data is automatically decrypted. The read and write performance of a file system is affected by the size of the data block that is accessed during each read or write operation. For example, you have two file systems of the same type and specifications. The performance of the file system for which the server-side encryption feature is enabled decreases by 5% to 25% compared with the performance of the other file system. For more information, see What is the read and write performance of a file system related to?

Is the available storage capacity of a file system reduced if I enable server-side encryption at rest for the file system?

No, the available storage capacity of the file system is not reduced. The Advanced Encryption Standard (AES) is a block cipher that uses the automatic padding mechanism. Data that is encrypted at rest with automatic padding does not occupy the available storage capacity of the file system.

Does NAS support the inotify subsystem?

No, NAS does not support the inotify subsystem. The inotifywait and rsync commands are commonly used together to back up and synchronize data in real time. However, the inotifywait command cannot be run as expected on NAS file systems due to the implementation of the inotify subsystem.

  • How inotifywait works

    The inotifywait command is a user-mode interface of the Linux inotify subsystem that is implemented at the Virtual File System (VFS) layer. After you run the inotifywait command, file changes are monitored at the VFS layer. If a file is created, deleted, or modified, the name of the file and the type of the operation are returned to the user-mode inotifywait process. Then, the inotifywait command returns the information about the operation.

  • Known issues
    The inotify subsystem is implemented at the VFS layer of the kernel. Therefore, the inotifywait process on a Network File System (NFS) client of an NFS file system cannot detect the operations that other clients perform on the file system. For example, a NAS file system is mounted on Client A and Client B at the same time. On Client A, when you start an inotifywait process to listen to the mount directory, the following issues may occur:
    • The inotifywait process can detect the operations that Client A performs on the files of the file system.
    • The inotifywait process cannot detect the operations that Client B performs on the files of the file system.
  • Alternative solution
    You can use the FAM subsystem as an alternative solution to resolve the issues. The File Alteration Monitor (FAM) subsystem is a repository that is used to listen to files or directories. FAM is implemented in user mode. An FAM daemon scans the directories in a file system on schedule to detect file changes. However, the FAM subsystem has the following drawbacks:
    • You must write code to call the required FAM operation on your client.
    • If you want to monitor a large number of files, the performance of the FAM subsystem may be compromised. A large number of resources may be consumed and the timeliness of file monitoring cannot be ensured.

If I cancel a file backup job, are the backup files of the job still retained?

No, all the backup files of the job are deleted from the backup vault. If you still need to back up these files, create another backup job.

If I cancel a restore job, are the restored files of the job retained after the restore job is canceled?

Yes, if you cancel a restore job, the restored files of the job are still stored in a specified directory. Other files of the job are no longer restored.

How is the free-trial period for backing up NAS files calculated?

You can use the backup feature free of charge for 30 days, starting from the day on which you create the first backup plan for a NAS file system.

For example, if you created a backup plan named backup01 for File System A on May 1, 2021, you can use the backup feature free of charge until May 30, 2021. After the free-trial period expires, you can delete the backup plan. If you want to continue using the backup plan, you must pay for the plan. For more information, see Billing methods and items.

Are deleted files temporarily stored in a recycle bin?

After you enable the recycle bin feature, the deleted files or directories are temporarily stored in the recycle bin, including but are not limited to the following files and directories:
  • Files that you delete from NAS file systems on compute nodes such as Elastic Compute Service (ECS) instances and containers. For example, if you delete the text01.text file by running the rm -f test01.text command, the test01.text file is dumped to the recycle bin.
  • Files or directories that are automatically deleted by applications from NAS file systems on compute nodes. For example, if the test02.text file is deleted by running the os.remove("test02.text") python code, the test02.text file is dumped to the recycle bin.
  • Files or directories that are deleted when you call the POSIX rename function. For example, the test_a.txt file and the test_b.txt file reside in the same directory. If you run the mv test_a.txt test_b.txt command, the test_b.txt file is dumped to the recycle bin.
  • Temporary files that are created by applications using NAS files. For example, if you run the vim command to edit a file, the .swp and .swpx temporary files are dumped to the recycle bin.
  • Application log files that are automatically rotated. For example, if you configure automatic log rotation by using NGINX, a maximum of 20 log files can be retained. When the test.log. 19 log file is rotated to the test.log. 20 log file, the original test.log. 20 log file is dumped to the recycle bin.
Note If you overwrite but do not delete the file, the file is not dumped to the recycle bin. For example, you call the open() function to open a file and write data into the file in w+ mode. The original file is not dumped to the recycle bin.

Can I restore a file from a recycle bin to the original directory of the file system if the directory is renamed?

Yes, you can restore a file from a recycle bin to its original directory regardless of whether the directory is renamed. This is because a restore job is performed based on the FileId of the original directory. For example, after the recycle bin feature is enabled, you delete the file1.txt file from the dir1 directory and change the directory name from dir1 to dir2. In the recycle bin of the NAS console, the directory tree indicates that the file1.txt file resides in the dir2 directory. After you restore the file from the recycle bin, the directory tree indicates that the file1.txt file is stored in the dir2 directory on the compute node.

Which way is faster, restoring files from the recycle bin or restoring files from a backup of the files?

When you restore files from the recycle bin, NAS migrates only the metadata of the files but not copy the files. Therefore, restoring files from the recycle bin is faster than restoring files from a backup of the files.

Am I charged when I use the recycle bin feature?

No, you are not charged when you use the recycle bin feature. However, you are charged for the used storage space of the temporary files in the recycle bin based on the pricing of the original storage type. For example, after you delete a file from a Capacity NAS file system, you are billed for the file based on the unit price of storage in Capacity NAS. After you delete a file from an IA storage medium, you are charged for the file based on the unit price of storage in the IA storage medium. For more information, see Billing of General-purpose NAS file systems and Billing of IA storage media. Before you delete a file from a Capacity NAS file system, you are charged for the file based on the storage unit price of Capacity NAS.

How do I query files in the recycle bin?

You can use the NAS console to query the files that are temporarily stored in the recycle bin and the time at which the files are deleted. For more information, see Query files in the recycle bin.

Can I read data from or write data to the files in the recycle bin?

No, you cannot read data from or write data to the files or directories in the recycle bin. You can only query deleted files and directories. If you enable the recycle bin feature, deleted files are temporarily retained in the recycle bin. Before you can read data from or write data to the files in the recycle bin, you must restore the files from the recycle bin. For more information, see Restore files from the recycle bin.