File Storage NAS：Mount an SMB file system

Install a CIFS client

Before you mount an SMB file system on a Linux ECS instance, you must install a Common Internet File System (CIFS) client. After you configure the Linux ECS instance, you no longer need to configure the Linux ECS instance the next time you mount a file system on the instance.

1. Connect to the Linux ECS instance. For more information, see Connection methods.

2. Install a CIFS client.

   Ubuntu and Debian

   Install the CIFS client by using the apt-get package manager.

   sudo apt-get update
   sudo apt-get install cifs-utils

   Red Hat Enterprise Linux (RHEL), CentOS, and Alibaba Cloud Linux

   Install the CIFS client by using the Yellowdog Updater, Modified (YUM) package manager.

   sudo yum install cifs-utils

   openSUSE and SLES12-SP2

   Install the CIFS client by using the Zypper package manager.

   sudo zypper install cifs-utils

   CoreOS

   Install the CIFS client by performing the following steps:

   1. Configure Security-Enhanced Linux (SELinux).

      sed -i 's/SELINUXTYPE=mcs/SELINUXTYPE=targeted/' /etc/selinux/config

   2. Compile the CIFS client package on a CoreOS ECS instance.

      You can perform the following steps to create a Fedora container and compile the CIFS client package. You can also download the CIFS client package that Alibaba Cloud provides for CoreOS, and then copy the package to the /tmp/ or /bin directory.

      1. Create a Fedora container and compile the cifs-utils package.

         docker run -t -i -v /tmp:/cifs fedora /bin/bash

      2. Run the following commands in sequence in the Docker environment:

         1. yum groupinstall -y "Development Tools" "Development Libraries"

         2. yum install -y bzip2

         3. curl https://download.samba.org/pub/linux-cifs/cifs-utils/cifs-utils-6.9.tar.bz2 --output cifs-utils-6.9.tar.bz2;

         4. bunzip2 cifs-utils-6.9.tar.bz2 && tar xvf cifs-utils-6.9.tar

         5. cd cifs-utils-6.9; ./configure && make

         6. cp mount.cifs /cifs/

         7. exit

Mount the SMB file system

SMB file systems can be manually or automatically mounted on Linux ECS instances. Manual mounting is suitable for temporary mounting. If you manually mount a NAS file system on an ECS instance, you must remount the file system every time the ECS instance is started or restarted. Automatic mounting is suitable for persistent mounting. If you enable automatic mounting for a NAS file system, you do not need to remount the file system every time the ECS instance is started or restarted. To prevent the mount information from being lost after the ECS instance is restarted, we recommend that you enable automatic mounting for a NAS file system after you manually mount the file system.

Manually mount the file system

You must use the mount target of the SMB file system to mount the SMB file system on a Linux ECS instance.

1. Connect to the Linux ECS instance. For more information, see Connection methods.

2. Run the following command to mount the file system:

   sudo mount -t cifs //file-system-id.region.nas.aliyuncs.com/myshare /mnt -o vers=2.1,guest,uid=0,gid=0,dir_mode=0755,file_mode=0755,mfsymlinks,cache=strict,rsize=1048576,wsize=1048576

   Command syntax: sudo mount -t cifs //<Domain name of the mount target>/myshare <Mount directory> -o <Mount options>

   Parameter	Description
   File system type	To mount an SMB file system on a Linux ECS instance, you must specify the -t cifs parameter.
   Domain name of the mount target	The domain name of the mount target is automatically generated when you create the mount target. Replace the domain name with the actual value. To obtain the domain name of the mount target, perform the following steps: Log on to the NAS console. On the File System List page, click the file system ID. Click the Mount Targets tab. Then, move the pointer over the icon in the Mount Target column.
   myshare	The name of the shared directory for the SMB file system. You cannot change the name after you specify this parameter.
   Mount directory	The path of the directory on which the SMB file system is mounted. For example, you can specify /mnt/sharepath.
   Mount options	Specify the required mount options by adding the -o parameter in the mount command: vers: the version of the SMB protocol. Specify 2.1 or later for the option. guest: the identity that you want to use to mount the file system. You must use the guest identity that is authenticated based on the New Technology LAN Manager (NTLM) protocol. rsize: the maximum size of a data packet that the SMB client can read from the SMB file system. In most cases, set this option to 1048576 (1 MB). wsize: the maximum size of a data packet that the SMB client can write to the SMB file system. In most cases, set this option to 1048576 (1 MB). Specify the mount options by adding the -o parameter: uid: the user to which the files in the file system belong after a successful mount. The default value of uid is 0. gid: the user group to which the files in the file system belong after a successful mount. The default value of gid is 0. dir_mode: the read, write, and execute permissions that you want to grant to the user on the specified directories. The value must start with 0, for example, 0755 and 0644. The default value of dir_mode is 0755. file_mode: the read, write, and execute permissions that you want to grant to the user on files. The value must start with 0, for example, 0755 and 0644. The default value of file_mode is 0755. mfsymlinks: specifies whether symbol links are supported. cache: If you set this option to strict, caching is enabled for the SMB client. The default value of cache is strict. If you set this option to none, caching is disabled for the SMB client. atime|relatime: If file access time does not affect your business, we recommend that you do not set this option to atime. The default value of this option is relatime. Note An authorized administrator of the Linux ECS instance has full control over the SMB file system. If you want to view the details of a mount target, run the mount | grep cifs command. We recommend that you use a Linux distribution whose kernel version is later than 3.10.0-514. If you use a Linux distribution whose kernel version is 3.7 or earlier, set the cache option to strict. You can run the uname -a command to view the kernel version.

3. Run the mount -l command to view the mount result.

   If a command output similar to the following example appears, the file system is mounted.

   

   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 Troubleshoot the failure of mounting an SMB file system on Linux.

4. Read data from and write data to the file system.

   You can access the SMB file system the same way you access a regular directory. The following figure shows an example.

   

(Optional) Automatically mount the file system

You can configure the /etc/fstab file of a Linux ECS instance to automatically mount an SMB file system when the ECS instance is restarted.

1. Open the /etc/fstab configuration file.

   //<Domain name of the mount target>/myshare /mnt cifs vers=3,guest,uid=0,gid=0,dir_mode=0755,file_mode=0755,mfsymlinks,cache=strict,rsize=1048576,wsize=1048576 0 0

   For more information, see Mount parameters. The following table describes the parameters that are not included in the preceding table.

   Parameter	Description
   0 (the first value after wsize)	Specifies whether to back up a file system by running the dump command. A non-zero value indicates that the file system is backed up. For a NAS file system, the default value is 0.
   0 (the second value after wsize)	The order in which the fsck command checks file systems at startup. For a NAS file system, the default value is 0, which indicates that the fsck command is not run at startup.

2. Run the reboot command to restart the ECS instance.

   Important

   If you restart the ECS instance, services are interrupted. We recommend that you perform the operation during off-peak hours.

3. Verify that automatic mounting is enabled.

   Note

   You can run the df -h command to check the mounted NAS file system within one minute after the ECS restarts.

Scenarios

To ensure optimal performance of the file system, you can specify mount options based on specific scenarios. This section lists scenarios and the mount options that are suitable for each scenario:

 mount -t cifs //file-system-id.region.nas.aliyuncs.com/myshare /mnt/sharepath -o vers=2.1,guest,mfsymlinks

Access control

To grant different permissions to different users, NAS allows you to authenticate users and control access to SMB file systems based on an Active Directory (AD) domain. After the mount target of an SMB file system is joined to an AD domain, AD users can access the SMB file system. Then, you can control access to files and directories in the SMB file system based on the AD domain.

For more information, see Join the mount target of an SMB file system to an AD domain and Mount and use an SMB file system on a Linux client as an AD domain user.