Managing General-Purpose File System Permissions

Overview

You can add authorization rules for a general-purpose file system to grant different permissions to different clients.

On the console, each new general-purpose file system has a default rule (Read/Write, no_root_squash, All IP addresses). This rule grants all client users read/write permissions to access the file system and does not map the root user to an unprivileged account. You can edit or delete this rule if needed.

Constraints

An IP address cannot be added to two authorization rules at the same time.

Authorized IP Addresses

You can configure authorized IP addresses using CIDR blocks.

A CIDR block uses a variable-length subnet mask to show the ratio of the network bits to host address bits within a range of IP addresses.

A suffix value is added at the end of an IP address to form a CIDR block. This suffix shows the bits of the network address. For example, 192.1.1.0/24 is an IPv4 CIDR block, in which the first 24 bits (192.1.1) are the network address.

Any IP address whose first 24 bits are the same as those of 192.1.1.0 will be applied with this authorization rule. In other words, 192.1.1.1 and 192.1.1.1/32 have the same effect.

Types of Permissions

There are read/write permissions and user permissions.

Adding Authorization Rules

You can add authorization rules on the console for permissions management.

1. Log in to the SFS console.
2. In the file system list, find the general-purpose file system you want to add authorization and click its name to go to its details page.
3. On the Permissions Management tab, click Add Authorization Rule.
   Figure 1 Add Authorization Rule
   

4. On the displayed page, add authorization based on Table 3.

   Table 3 Parameter description

   Parameter	Description
   VPC	Select the VPC you want to add, for example, vpc-30e0. If no VPC is available, create one.
   Authorizations	You can select Read/Write or Read-only. Read/Write is preselected.
   User Authorizations	You can select no_root_squash, root_squash, or all_squash. no_root_squash allows the root user on the client to access the general-purpose file system as root. root_squash allows the root user on the client to access the general-purpose file system as the nobody user. all_squash allows any user on the client to access the general-purpose file system as the nobody user, and the user can modify and delete the file system.
   Authorized Addresses	You can select All IP addresses or Specific IP address/CIDR block. All IP addresses is preselected. Enter a valid IPv4 address or range that is not starting with 0 except 0.0.0.0/0. If you add 0.0.0.0/0, any IP address within this VPC will be authorized to access the file system. Do not enter an IP address or IP address range starting with any number ranging from 224 to 255, for example 224.0.0.1 or 255.255.255.255, because class D and class E IP addresses are not supported. IP addresses starting with 127 are also not supported. If you enter an invalid IP address or IP address range, the rule may fail to be added, or the authorization will not work. If you enter an IP address range, enter it in the format of IP address/mask. For example, enter 192.168.1.0/24. Do not use the following format:192.168.1.0-255 or 192.168.1.0-192.168.1.255. The number of bits in a subnet mask must be an integer ranging from 0 to 31, and mask value 0 is valid only in 0.0.0.0/0. For details about IP address ranges, see Authorized IP Addresses. NOTE: If you select Specific IP address/CIDR block, you can add multiple IP addresses or CIDR blocks. Enter each one on a separate line. After the authorized addresses are added, you can click the number shown under Authorized Addresses in the permissions management list to check their information.

5. Confirm the information and click OK.

Related Operations

You can click Edit in the Operation column of a rule to modify the read/write permission and user permission, or click Delete to delete a rule.