This topic describes the limits of Apsara File Storage NAS (NAS) on service specifications, operating systems, protocols, networks, and features.
Limits on service specifications
Item | Description |
Maximum number of file systems that can be created in each region within an Alibaba Cloud account |
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Maximum number of mount targets for a single file system |
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Maximum number of files in a single file system |
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Maximum number of directory levels in a single file system | 1,000 levels |
Maximum capacity of a single file system |
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Maximum number of compute nodes on which a file system can be mounted at the same time | 1,000 |
Maximum size of a single file | 32 TiB |
Maximum number of hard links to a single file | 511 |
Maximum number of permission groups that can be created in each region within an Alibaba Cloud account | 20 |
Maximum number of rules that can be created for a permission group | 300 |
Limits on throughput
The following table describes the maximum throughput of each storage class of General-purpose NAS file systems in the China (Hong Kong) region and regions outside the Chinese mainland. To increase the throughput, submit a ticket.
Storage class | Region | Zone | Maximum read throughput (GB/s) | Maximum write throughput (GB/s) |
Capacity NAS file system | China (Hong Kong) | Hong Kong Zone B | 10 | 2 |
Japan (Tokyo) | Tokyo Zone A | 10 | 1 | |
Tokyo Zone B | 3 | 0.5 | ||
India (Mumbai) | Mumbai Zone A | 10 | 1 | |
Singapore | Singapore Zone A | 10 | 1 | |
Singapore Zone C | 10 | 1 | ||
Australia (Sydney) | Sydney Zone A | 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 NAS file system | Malaysia (Kuala Lumpur) | Kuala Lumpur Zone A | 10 | 1 |
Performance NAS file system | Japan (Tokyo) | Tokyo Zone A | 10 | 1 |
Tokyo Zone B | 10 | 1 | ||
South Korea (Seoul) | Seoul Zone A | 10 | 1 | |
India (Mumbai) | Mumbai Zone A | 10 | 1 | |
Singapore | Singapore Zone A | 10 | 2 | |
Singapore Zone C | 10 | 1 | ||
Australia (Sydney) | Sydney Zone A | 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 |
Limits on operating systems
Item | Description |
Image | The NAS product team has tested the kernel images and listed the recommended images for NAS. To ensure the optimal performance of NAS file systems, use the recommended kernel versions or later versions. If you do not use the recommended kernel images, NAS may become unavailable. For more information, see Recommended kernel images. |
Kernel version | The NAS product team has identified some defective kernel versions and provided solutions. If you use a defective kernel version and do not upgrade the version, NAS may become unavailable. If the NAS product team identifies new issues about the adaption of kernel versions, Alibaba Cloud pushes notifications to you by using emails, internal messages, text messages, and console announcements. Make sure that the preceding communication channels are available and handle the issues at the earliest opportunity. For more information, see Known issues on NFS clients. |
macOS | You can mount only Server Message Block (SMB) file systems on macOS. |
AIX | Not supported. |
Limits on protocols
Network File System (NFS) file systems
Item | Description |
Naming conventions | The name of a file cannot exceed 255 bytes in length. |
Protocol versions | Only NFSv3 and NFSv4.0 are supported. |
File features | The POSIX SetUID, SetGID, and sticky bit features are not supported. |
NFSv4.0 attributes | The following attributes are not supported:
If you use an unsupported attribute, an |
NFSv4.0 operations | The following operations are not supported:
If you call an unsupported operation, an |
NFSv4.0 features | The delegation feature is not supported. |
UIDs and GIDs |
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NFS clients |
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File and directory types | Extreme NAS file systems support the following types of files and directories: REG, DIR, SYMLINK, and LINK. |
SMB file systems
Item | Description |
Naming conventions | The name of a file cannot exceed 255 UTF-16 characters in length. |
Features |
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Protocol versions | SMB 2.1 and later are supported. |
SMB clients | Each file or directory can be opened by up to 8,192 users at a time. This limit applies across all compute nodes on which the file system is mounted and all users that share access to the file system. This indicates that each file or directory can have up to 8,192 active file handles. A file system can have a maximum of 65,536 active file handles. |
Limits on networks
Item | Description |
Classic network |
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Network of General-purpose NAS file systems | General-purpose NAS file systems use the new-generation high-performance network transmission channel of Alibaba Cloud. This channel does not support custom TCP options. If you use custom TCP options, the NAS file system may fail to be mounted. |
Limits on lifecycle policies
Item | Description |
File system type | Only General-purpose NAS file systems support lifecycle policies. |
Number of lifecycle policies | You can create a maximum of 20 lifecycle policies in each region within an Alibaba Cloud account. |
Limits on directory quotas
Item | Description |
File system type | Only General-purpose NFS file systems support quota management. |
Quota | For a single file system, you can configure quotas for a maximum of 500 directories. The maximum directory depth is eight levels. For example, the depth of the root directory / is zero level. The depth of the /workspace directory is one level. The depth of the /workspace/dir1 directory is two levels. |