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    Simple Application Server:simple application server limits

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    Simple Application Server:simple application server limits

    Last Updated:Mar 02, 2026

    Simple Application Server imposes limits on product features and service performance. Review these limits before use to ensure they meet your business requirements. This topic describes the resource limits for Simple Application Server.

    Server

    Limitations

    Limitations

    Instance quantity

    By default, a single Alibaba Cloud account can have a maximum of 50 instances in a region. This quota is shared across Simple Application Server instances. To request a quota increase, see View or increase instance quotas.

    Virtualization software and secondary virtualization

    You cannot install virtualization software or perform secondary virtualization.

    Sound card applications

    Sound card applications are not supported.

    Attaching external hardware devices

    You cannot attach external hardware devices, such as hardware dongles, USB flash drives, external hard drives, or USB security keys.

    image

    Restrictions

    Limitations

    Custom image

    A single Alibaba Cloud account can have a custom image quota of three times its number of server instances, with a maximum of 15 images.

    Cross-account image sharing

    • Images can only be shared with accounts in the same region.

    • You can share each custom image with up to 10 primary Alibaba Cloud accounts. Sharing with Resource Access Management (RAM) users is not supported.

    • Sharing images between China site accounts and international site accounts is not supported.

    • When you share a custom image that includes a data disk, the data disk itself is not shared.

    For more information, see Share custom images across accounts.

    Application or system images

    Some images include pre-installed software in the /home/staragent/ and /usr/local directories, such as /usr/local/aegis and /usr/local/cloudmonitor. This software consists of environment-dependent programs and library files. Do not modify them.

    Releasing a custom image

    Releasing a SAS instance also releases any custom images created from it.

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

    Storage

    Limitations

    Limitations

    Number of system disks per instance

    1 piece

    Number of data disks per instance

    A maximum of one data disk can be attached.

    Data disk capacity

    0–16,380 GiB

    Data disk mount point

    /dev/vdb

    Detaching a data disk

    A data disk expires with its attached instance and cannot be detached.

    Renewing a data disk

    After a data disk is attached, the instance and the data disk must be renewed together. You cannot renew the instance or the data disk separately.

    Snapshot

    Limitations

    Limitations

    Number of snapshots per server

    You can create a maximum of three snapshots for each server.

    Snapshot quota per account

    A single Alibaba Cloud account can have a snapshot quota of three times its number of server instances, with a maximum of 15 snapshots.

    Scheduled snapshots

    Only manual snapshot creation is supported.

    Rolling back a disk from a snapshot

    Although snapshots are retained after a system reset or image change, you cannot use them to roll back the disk.

    Releasing a snapshot

    If a SAS instance expires and is released, its corresponding snapshots are also released.

    Downloading or exporting a snapshot

    You cannot download or export snapshots.

    For more information about snapshots, see Manage snapshots.

    Network

    Limitations

    Limits

    Public IP address

    Each SAS instance comes with a default public IP address. You cannot change this IP address, and it is not retained after the instance expires.

    IPv6 address

    Simple Application Server does not currently support IPv6 address configuration.

    Bandwidth

    • Simple Application Server bandwidth is symmetrical. The bandwidth specified in your plan is the unified peak for both inbound and outbound traffic. For example, if you purchase a Simple Application Server plan with 5 Mbps bandwidth, the server's peak outbound bandwidth is 5 Mbps, and its peak inbound bandwidth is also 5 Mbps.

    • The Internet bandwidth in your Simple Application Server plan represents a peak value for both outbound and inbound traffic and is not a performance guarantee. During peak business hours, network resource contention may lead to bandwidth limitations or packet loss. This service is unsuitable for applications that require guaranteed public network quality. If your business requires a high-quality public network connection, purchase an Elastic Compute Service (ECS) instance with a fixed-bandwidth plan.

    Firewall

    • You can create a maximum of 50 firewall rules for a single server.

    • You cannot use port 25 on a SAS instance to send outbound emails. To send emails, use port 465.

    For more information, see Manage firewalls.

    Internal network communication

    By default, all SAS instances under the same Alibaba Cloud account and within the same region can communicate with each other over the internal network. By default, they cannot communicate over the internal network with other Alibaba Cloud products in a Virtual Private Cloud (VPC), such as ECS instances or ApsaraDB instances. To enable this communication, you can manage the VPC connection. For more information, see Manage VPC connections.