Mount a file system on a Linux ECS instance - Storage Services Overview

Before you access an Apsara File Storage NAS file system, you must create a NAS file system and mount the file system to an Elastic Compute Service (ECS) instance. This topic describes how to create a Network File System (NFS) file system in the NAS console. This topic also describes how to mount the NFS file system on an ECS instance of CentOS 8.2 in a virtual private cloud (VPC). You can then upload data to or download data from the file system.

Prerequisites

The NAS service is activated.
To activate the NAS service, go to the NAS service page and perform the operations as prompted.
An ECS instance of CentOS 8.2 is created in the China (Hangzhou) region. For more information, see Create an instance.

Step 1: Create an NFS file system and create a mount target for the file system

Log on to the NAS console.
In the File System Selection Guide section of the Overview page, click Create a Common NAS File System.

On the Create a Common NAS File System page, set the required parameters. The following table describes the parameters. For other parameters, select values based on your business requirements or use the default values.


Parameter	Description
Region	Select China (Hangzhou).
Zone	Select Hangzhou Zone B. Select the zone where the ECS instance resides.
Protocol Type	Select NFS.
Network Type	Select VPC.
VPC	Select the VPC where the ECS instance resides.
VSwitch	Select a vSwitch that resides in the VPC.

Click Buy Now and complete the payment as prompted.

Step 2: Mount the file system

Connect to the ECS instance. For more information, see Guidelines on instance connection.
Run the following command to install an NFS client:
```
sudo yum install nfs-utils
```

Run the following command to set the number of concurrent NFS requests to 128:

if (lsmod | grep sunrpc); then
(modinfo sunrpc | grep tcp_max_slot_table_entries) && sysctl -w sunrpc.tcp_max_slot_table_entries=128
(modinfo sunrpc | grep tcp_slot_table_entries) && sysctl -w sunrpc.tcp_slot_table_entries=128
fi
(modinfo sunrpc | grep tcp_max_slot_table_entries) && echo "options sunrpc tcp_max_slot_table_entries=128" >> /etc/modprobe.d/alinas.conf
(modinfo sunrpc | grep tcp_slot_table_entries) && echo "options sunrpc tcp_slot_table_entries=128" >> /etc/modprobe.d/alinas.conf

Run the following command to mount the file system by using the NFSv3 protocol:
```
sudo mount -t nfs -o vers=3,nolock,proto=tcp,rsize=1048576,wsize=1048576,hard,timeo=600,retrans=2,noresvport file-system-id.region.nas.aliyuncs.com:/ /mnt
```
file-system-id.region.nas.aliyuncs.com:/ /mnt is in the format of <Domain name of the mount target>:<Mount directory of the file system><Path of the mount directory>. Replace the values based on your actual scenarios.
Run the mount -l command to view the mount result.

The command output in the following figure indicates a successful mount. After the file system is mounted, you can run the df -h command to view the capacity of the file system.

If the file system fails to be mounted, troubleshoot the issue. For more information, see Fix mount issues.

Step 3: Upload and download data

After you mount a NAS file system on an ECS instance, you can access the file system as a local directory. The following code shows an example: Read and write operations