Restrictions and Limitations

General

To obtain better performance, you are advised to use the operating systems listed in Supported Operating Systems, which have passed the compatibility test.
Currently, SFS does not support replication.
Currently, SFS does not support cross-region access.

SFS Turbo

**Table 1** SFS Turbo restrictions
Item	General
Access method	VPN, Direct Connect, and Cloud Connect
Max. bandwidth	2 GB/s
Max. IOPS	100,000
Min. latency	1 to 2 ms
Max. capacity per file system	320 TB
Supported protocol	NFSv3
Max. number of clients per file system	500
Max. number of authorized VPCs per file system	20
Max. size of a single file	16 TB
Max. number of files or subdirectories per file system	1 billion
Max. number of files or subdirectories in a single directory	20 million NOTE: If you need to execute the ls, du, cp, chmod, or chown command on a directory, you are advised to place no more than 500,000 files or subdirectories in that directory. Otherwise, requests may take long times as the NFS protocol sends a large number of requests to traverse directory files and requests are queueing up.
Max. directory depth (unit: layer)	100
Max. path length (unit: byte)	1,024
Max. soft link length (unit: byte)	1,024
Max. hard link length (unit: byte)	255
Max. number of file systems	32 by default. You can submit a service ticket to increase the quota.
File system backup	Supported
Backup data restoring to the original file system	Not supported NOTE: SFS Turbo uses single-AZ deployment. SFS Turbo file systems will fail if their AZ fails.
File locking with Flock	Not supported
Cross-region mounting via domain name	Not supported NOTE: When you mount a file system using its domain name, cross-region mounting is not supported. To mount a file system across regions, use the file system IP address for mounting. The file system domain name randomly resolves to a corresponding domain name server IP address, so some domain name servers may have lots of mounts while others have only a few. It is recommended that you use the domain name servers to the maximum extent as uneven mounts may affect the file system performance.
Cache acceleration	Not supported
File system tagging	A maximum of 10 tags can be added to a file system. Tag keys of a file system must be unique.