Limits on Simple Application Server resources - Simple Application Server

Simple Application Server has limits on features and service performance. Before using it, we recommend that you understand these limits. This topic describes the resource limits for Simple Application Server.

Servers

Limit	Description
Instance quota	The total number of Simple Application Server,. You can purchase up to 50 instances under the same Alibaba Cloud account, in the same region. To increase the quota, see View or increase instance quotas.
Installation of virtualization software and secondary virtualization	Simple Application Server does not support virtualization software or secondary virtualization.
Sound card applications	Simple Application Server does not support sound card applications.
Loading of external hardware devices	You cannot directly load external hardware devices, such as hardware dongles, USB flash drives, external hard disks, or USB keys for online banking.

Images

Limit	Description
Custom image	The maximum number of custom images under an Alibaba Cloud account is triple the number of servers. Cannot exceed 15.
Cross-account image sharing	You can share images across accounts only within the same region. Each custom image can be shared with a maximum of 10 Alibaba Cloud accounts. You cannot share custom images with RAM users. Images cannot be shared between China site (aliyun.com) and international site (alibabacloud.com). The shared custom image does not contain the data disk. For more information, see Share custom images across accounts.
Application image or OS image	Some images have pre-installed software in the `/home/staragent/` and `/usr/local` directories, such as `/usr/local/aegis` and `/usr/local/cloudmonitor`. These are environment-dependent programs and library files. Do not modify them.
Release of custom images	If a server is released, the custom images are also released.

For more information about custom images, see Manage custom images.

Storage

Limit	Description
Number of system disks on a single instance	1
Number of data disks on a single instance	Only one data disk can be attached.
Data disk capacity	0 to 16380 GiB
Data disk mount target	`/dev/vdb`
Uninstall a data disk	The data disk is attached to the instance with the same expiration date and cannot be uninstalled.
Renew a data disk	The data disk must be renewed together. You cannot renew the instance or the data disk separately.

Snapshots

Limit	Description
Number of snapshots that can be created for a single server	You can create a maximum of three snapshots.
Maximum number of snapshots for an Alibaba Cloud account	The maximum number of snapshots that can be retained for an Alibaba Cloud account is three times the number of created servers. The total number of snapshots cannot exceed 15.
Scheduled snapshots	You can only create snapshots manually. Scheduled snapshots are not supported.
Disk rollback using a snapshot	Snapshots that are created before you reset the system or change the image are retained after the operation, but cannot be used to roll back the disk.
Release of snapshots	If a Simple Application Server instance is released, the snapshots of the server are also released.
Download or export a snapshot	You cannot download or export snapshots.

For more information about snapshots, see Manage snapshots.

Network

Limit	Description
Public IP address	By default, each instance is configured with a public IP address. You cannot change the public IP address. You cannot retain the public IP address after the server expires.
IPv6 address	You cannot configure IPv6 addresses for instances.
Bandwidth	The inbound and outbound bandwidths are equal when the bandwidth exceeds 10 Mbit/s. The rules are based on the 10 Mbit/s threshold: If the peak outbound bandwidth is less than or equal to 10 Mbit/s, Alibaba Cloud allocates an inbound bandwidth of 10 Mbit/s. If the peak outbound bandwidth is greater than 10 Mbit/s, Alibaba Cloud allocates an inbound bandwidth that is equal to the peak outbound bandwidth. The public bandwidth is the maximum rate of inbound or outbound Internet data transmission. This metric is not guaranteed. During peak hours, if resource contention occurs, bandwidth may be limited, and packet loss may occur. Simple application servers are not suitable for scenarios with strict requirements for Internet connection quality. If your business requires high-quality Internet connections, we recommend purchasing Elastic Computing Service (ECS) instances that use pay-by-bandwidth billing.
Firewall	You can create a maximum of 50 firewall rules for a single server. Port 25 of a Simple Application Server instance cannot be used to send emails to external destinations. To send emails, use port 465. For more information, see Manage firewalls.
Service interconnection	By default, all instances that belong to the same Alibaba Cloud account in the same region can communicate over the internal network. By default, servers cannot communicate over the internal network with other Alibaba Cloud products, even in a virtual private cloud (VPC). For example, ECS instances and ApsaraDB. You can enable service interconnection to establish connections. For more information, see Manage service interconnection.