Limits and quotas

Item

Description

Maximum number of file systems per account in a region

• General-purpose NAS: 20

• Extreme NAS: 200

Maximum number of mount targets per file system

• General-purpose NAS: 2

• Extreme NAS

  • File systems created before January 19, 2024: 1

  • File systems created on or after January 19, 2024: 2

Maximum number of files per file system

• General-purpose NAS: 1 billion

• Extreme NAS: 500 million

Maximum directory depth per file system

1,000

Maximum capacity per file system

• Capacity NAS: 10 PiB

• Premium NAS: 1 PiB

• Performance NAS: 1 PiB

• Extreme NAS: 256 TiB

Maximum number of compute nodes that can concurrently mount a file system

1,000

Maximum size of a single file

32 TiB

Maximum number of hard links per file

511

Maximum number of permission groups per account in a region

20

Maximum number of permission group rules per permission group

300

Storage type

Region

Zone

Read throughput (GB/s)

Write throughput (GB/s)

Capacity

China (Hong Kong)

Hong Kong Zone B

10

2

Japan (Tokyo)

Tokyo Zone A

10

1

Tokyo Zone B

3

0.5

Singapore

Singapore Zone A

10

1

Singapore Zone C

10

1

Malaysia (Kuala Lumpur)

Kuala Lumpur Zone A

10

1

Indonesia (Jakarta)

Jakarta Zone A

10

1

Philippines (Manila)

Manila Zone A

10

1

US (Virginia)

Virginia Zone B

10

1

US (Silicon Valley)

Silicon Valley Zone B

10

1

UK (London)

London Zone A

10

1

Germany (Frankfurt)

Frankfurt Zone A

10

1

Premium

Malaysia (Kuala Lumpur)

Kuala Lumpur Zone A

10

1

Performance

Japan (Tokyo)

Tokyo Zone A

10

1

Tokyo Zone B

10

1

South Korea (Seoul)

Seoul Zone A

10

1

Singapore

Singapore Zone A

10

2

Singapore Zone C

10

1

Malaysia (Kuala Lumpur)

Kuala Lumpur Zone A

10

1

US (Virginia)

Virginia Zone A

10

1

US (Silicon Valley)

Silicon Valley Zone B

10

1

UK (London)

London Zone A

10

1

Germany (Frankfurt)

Frankfurt Zone A

20

3

Item

Description

Image

NAS is fully tested on a range of operating system images. For optimal performance, we recommend that you use our recommended kernel images or their later versions. NAS availability is not guaranteed on images that are not on the recommended list. For more information, see Recommended kernel images.

Kernel version

NAS has identified issues with certain kernel versions and provided solutions. If you use a problematic kernel version without upgrading, NAS availability is not guaranteed. We notify you of new kernel compatibility issues through email, internal messages, SMS, and console announcements. Ensure that your communication channels are open to receive these updates and address them promptly. For more information, see Known issues on NFS clients.

macOS

macOS supports mounting only SMB file systems.

AIX

Not supported.

Item

Description

Naming conventions

The maximum length of a filename is 255 bytes.

Protocol versions

Only NFSv3 and NFSv4.0 are supported.

File features

NAS does not support the POSIX SetUID, SetGID, and sticky bit features.

NFSv4.0 attributes

NAS does not support the following attributes:

• FATTR4_MIMETYPE

• FATTR4_QUOTA_AVAIL_HARD

• FATTR4_QUOTA_AVAIL_SOFT

• FATTR4_QUOTA_USED

• FATTR4_TIME_BACKUP

• FATTR4_TIME_CREATE

• FATTR4_ARCHIVE

If you use any of these attributes, an NFS4ERR_ATTRNOTSUPP error is logged in the /var/log/messages file.

NFSv4.0 operations

NAS does not support the following operations:

• OP_DELEGPURGE

• OP_DELEGRETURN

• NFS4_OP_OPENATTR

If you use any of these operations, an NFS4ERR_ATTRNOTSUPP error is logged in the /var/log/messages file.

NFSv4.0 features

NAS does not support the delegation feature.

UID and GID

• For the NFSv3 protocol, if a local Linux account exists for the user ID (UID) or group ID (GID) of a file owner, the corresponding username and group name are displayed. Otherwise, the UID and GID are displayed directly.

• For the NFSv4.0 protocol, if the Linux kernel version is earlier than 3.0, the UID and GID for all files are displayed as nobody. If the kernel version is 3.0 or later, the same rule as for NFSv3 applies.

  Note

  If you mount a file system by using the NFSv4.0 protocol on a Linux client with a kernel version earlier than 3.0, we recommend that you do not run the chown or chgrp command on files or directories. Otherwise, the UID and GID of the file or directory are changed to nobody.

NFS client limits

• For General-purpose NAS, a single NFS client allows a maximum of 128 concurrent requests.

• For General-purpose NAS, the maximum combined read and write bandwidth for a single NFS client is 500 MB/s.

• An NFS client can have a maximum of 32,768 files open simultaneously. Files in a directory that is only being enumerated (for example, with the 'ls' command) are not counted as open files.

• Each mount on an NFS client can acquire up to 8,192 locks on a maximum of 256 files or processes. For example, a single process can acquire one or more locks on 256 separate files, or eight processes can each acquire one or more locks on 32 files.

• Using an NFS client on a Windows operating system to access an NFS file system is not recommended.

File and directory types

Extreme NAS file systems support the following file and directory types: REG, DIR, SYMLINK, and LINK.

Item

Description

Naming conventions

The maximum length of a filename is 255 UTF-16 characters.

Feature limits

• Extended attributes and lease-based client caching are not supported.

• IOCTL or FSCTL operations such as sparse files, file compression, network interface status queries, and reparse points are not supported.

• Alternate data streams are not supported.

• LDAP-based identity authentication is not supported.

• The following SMB features are not supported: SMB Direct, SMB Multichannel, SMB Directory Leasing, and Persistent File Handles.

Protocol versions

SMB 2.1 and later versions are supported.

SMB client limits

A single file or directory can have a maximum of 8,192 concurrent opens (active file handles) from all users and compute nodes. A file system can have a maximum of 65,536 active file handles.

Item

Description

Classic network

• You cannot mount a NAS file system on an ECS instance that belongs to a different Alibaba Cloud account.

• The IP address of a mount target may change due to kernel limitations, which can make the NAS file system inaccessible.

  Alibaba Cloud notifies you of mount target IP address changes 30 days in advance through methods such as email, internal messages, SMS, voice calls, and console announcements. You must remount the file system within 30 days of receiving the notification.

General-purpose NAS network

General-purpose NAS uses a new generation of high-performance network transport links from Alibaba Cloud. These links do not support custom TCP options. Using custom TCP options may cause mount failures.

Item

Description

File system type

Only General-purpose NAS file systems support lifecycle policies.

Number of policies

You can create a maximum of 20 lifecycle policies per Alibaba Cloud account in a region.

Item

Description

File system type

Only General-purpose NAS NFS file systems support directory quotas.

Quota

For a single file system, you can set quotas on a maximum of 500 directories. The maximum supported directory depth is 8 levels. For example, the root directory / is at depth 0, /workspace is at depth 1, and /workspace/dir1 is at depth 2.

Item

Description

Number of tags

You can add a maximum of 20 tags to each file system.

Tag key

The tag keys for a single file system must be unique.

Region

Tags are isolated by region. For example, tags added in the China (Hangzhou) region are not visible in the China (Shanghai) region.

Item

Description

Maximum capacity per AgenticFS

500,000 PiB

Maximum number of files per AgenticFS

500 trillion

Creation permissions

This feature is available only to users on the allowlist. To request access, submit a ticket.

Protocols and clients

Only the NFSv3 protocol and Linux clients are supported. The SMB protocol, Windows, and macOS are not supported.

Compute nodes

AgenticFS can be mounted on Linux compute nodes that support NFSv3, such as ECS instances and other Alibaba Cloud services like Agent Sandbox.

Number of AgenticSpaces

A single AgenticFS file system supports a maximum of 500,000 AgenticSpaces.

Region support

This feature is currently available only in allowlisted regions. For more information, see Supported regions for features.

Item

Description

Maximum capacity per AgenticSpace

1 PiB

Maximum number of files per AgenticSpace

1 billion

Capacity quota

Required at creation. Can be increased in 4 GiB increments. Only one capacity quota is supported per AgenticSpace.

File count quota

Required at creation.

Quota modification

The new quota must be greater than or equal to the current usage. Otherwise, the modification fails.

Path limits

The parent directory for an AgenticSpace path must already exist. Only single-level directories are supported; nested AgenticSpaces are not allowed. The path cannot be renamed or be a symbolic link.