FAQ

Are there any restrictions on the use of file storage?

File storage has certain restrictions on file system capacity, maximum file length, protocol version, etc. Please refer to the “Product Restrictions” chapter for detailed information.

What access protocols does file storage support?

Currently, newly created instances of capacity-oriented file storage products support both NFS and SMB protocols, while newly created instances of performance-oriented file storage products only support the NFS protocol.

Does file storage allow cross-regional access?

The network of file storage products is based on VPC. On the UFS console, you can specify hosts under multiple VPCs in the same region as the file system instance to access it. If you need to access the file system from another region, you can connect the VPC where the host needing to access the file system is located with the VPC where the file system’s mount point is located through the UDPN service. We strongly recommend that the file system and the hosts using it be in the same region, as the UDPN service may incur additional fees and result in higher latency than same-region access.

Does file storage allow cross-project group access?

The network of file storage products is based on VPC. On the UFS console, users are allowed to specify hosts under multiple VPCs in the same project group as the file system instance to access it. VPCs not in this project group are not allowed to create mount points by default. You can connect the VPCs corresponding to the project group where the host needing to access the file system is located and the project group where the file system’s mount point is located on the VPC page.

Linux NFS client kernel defect

Since the file storage service relies on the NFS client service, and the implementation of the NFS client on Linux has some defects, it may lead to serious problems such as unresponsive IO.

We strongly recommend that you upgrade your host to the above recommended kernel versions. If you cannot upgrade and encounter unresponsive operations, you need to restart the host to recover.

Linux SMB client kernel defect

Due to some defects in the implementation of SMB clients in early versions of Linux, it may lead to serious problems such as unresponsive IO.

We strongly recommend that you upgrade your host to the above recommended kernel versions. If you cannot upgrade and encounter unresponsive operations, you need to restart the host to recover.

Is there a limit to the number of host clients that can access a single file system?

Client hosts access through the mount point corresponding to the file system. Since the mount point restricts the allowed VPCs rather than specific host IPs, any number of hosts within the VPC are allowed to access as long as you reasonably plan the size of each subnet in the VPC. Although we have certain restrictions on the number of mount points (for details, refer to the “Product Restrictions” chapter), there is no limit on the number of hosts allowed to access via the mount points.

Can physical cloud and hosted cloud hosts access file storage?

Physical cloud hosts can access file storage by choosing their VPC on the file storage console and setting up mount points. However, hosted cloud VPCs are not allowed to be connected on the file storage console by default. You need to contact the hosted cloud technical support to enable the VPC where the hosted cloud host is located and the VPC where the file system mount point is located to access.

How to change the concurrency of NFS requests?

The NFS client limits the number of concurrent requests allowed. In many distribution kernels, this default value is usually 2, which results in low throughput due to low concurrency. Therefore, to improve performance for a single client, it is recommended to modify this parameter.

Step One, Install NFS Client

For detailed instructions on installing the NFS client, please refer to the “Mount File System” section in the “Operations Guide” chapter.

Step Two, Modify System Parameters

Run the following command with root permission in the command line (this operation only needs to be performed once after the first time of the NFS Client installation is complete, and does not need to be run multiple times):

echo "options sunrpc tcp_slot_table_entries=128" >> /etc/modprobe.d/sunrpc.conf

echo "options sunrpc tcp_max_slot_table_entries=128" >> /etc/modprobe.d/sunrpc.conf

Step Three, Mount File System

For detailed instructions on mounting the file system, please refer to the “Mount File System” section in the “Operations Guide” chapter.

Step Four, Modify System Parameters Again

Modify the relevant system parameters by executing the following command:

sysctl -w sunrpc.tcp_slot_table_entries=128

After completing this, unmount the file system and re-mount it. Then run the following command to view the system parameter values. If the return value is 128, it means the setting is successful.

cat /proc/sys/sunrpc/tcp_slot_table_entries

Can the storage type (capacity-oriented, performance-oriented) of file storage be modified?

No. Currently, it is not possible to modify the storage type of an existing file system instance. If you have such a need, you can create a new file system instance and migrate the data from the old file system instance.

Are there any special operations required before deleting a file system?

Yes. Before deleting a file system, ensure that the data in it will no longer be used. Currently, file storage does not provide data recovery functions, so delete operations should be performed with caution. Before deleting the file system, ensure that all hosts using the file system have unmounted it; otherwise, residual deleted file system instances on the host may affect host operation.

How to resolve the “no permission” error when using file storage on Windows?

• Cause: The NFS protocol uses GID and UID for identity verification. By default, the GID and UID values on Windows are -2, which causes the “no permission” error when operating the file system.

• Solution:

1. Open a Command Prompt window, and type regedit to enter the registry editor page.
2. Select the following values: HKEY_LOCAL_MACHINE > SOFTWARE > Microsoft > ClientForNFS > CurrentVersion > Default.
3. Right click Default, select New > DWORD(32-bit) value and create AnonymousGID and AnonymousUID two registry items.

How to solve the problem of the client getting stuck when Windows uses a file system to create files\folders?

• Problem cause: By default, Windows clients will use Server Message Block (SMB) ports 139 and 445 to access mounted file systems. As the file system is mounted using the NFS protocol, requests sent to ports 139 and 445 will remain unresponsive, causing the client to get stuck.

• Solution:

  Scheme one: Use SMB protocol to mount file system.

  Scheme two: If you are sure not to use the SMB protocol, you can close the smb client service using the following steps.

  1. Click on the start menu button in the lower left corner, open Windows Management Tools.
  2. Double-click Services.
  3. Find Workstation service.
  4. Right click Properties, in the General tab, set the startup type to Disabled and the service status to Stopped. In the Recovery tab, set the action type for First failure, Second failure, and Subsequent failures to No action. After the modification is completed, click Apply and OK.
  5. After modification, there will be no more client crashes when using the file system. If you need to use the SMB protocol in the future, you can start the Workstation service again.

How to resolve the “invalid device” error when renaming files/folders using file storage on Windows?

• Problem Cause: NFS protocol implementation issue.

• Solution: Due to the NFS protocol implementation, when the file system is mounted to a subdirectory, renaming operations return an “invalid device” error. Please mount the root directory of the file system for use.