What Are the Differences Between SFS, OBS, and EVS?

Table 1 shows the comparison between SFS, OBS, and EVS.

**Table 1** Comparison between SFS, OBS, and EVS
Dimension	SFS	OBS	EVS
Concept	SFS provides on-demand high-performance file storage, which can be shared by multiple ECSs. SFS is similar to a remote directory for Windows or Linux OSs.	OBS provides massive, secure, reliable, and cost-effective data storage for users to store data of any type and size.	EVS provides scalable block storage that features high reliability and high performance to meet various service requirements. An EVS disk is similar to a hard disk on a PC.
Data storage logic	Stores files. Data is sorted and displayed in files and folders.	Stores objects. Files can be stored directly to OBS. The files automatically generate corresponding system metadata. You can also customize the metadata if needed.	Stores binary data and cannot directly store files. To store files, you need to format the file system first.
Access method	SFS file systems can be accessed only after being mounted to ECSs or BMSs through NFS or CIFS. A network address must be specified or mapped to a local directory for access.	OBS buckets can be accessed through the Internet or Direct Connect. The bucket address must be specified for access, and transmission protocols HTTP and HTTPS are used.	EVS disks can be used and accessed from applications only after being attached to ECSs or BMSs and initialized.
Application Scenario	Gene sequencing, image rendering, media processing, file sharing, content management, and web services	Big data analysis, static website hosting, online video on demand (VoD), gene sequencing, and intelligent video surveillance	Industrial design, energy exploration, critical clustered applications, enterprise application systems, and development and testing
Capacity	PB-scale	EB-scale	TB-scale
Latency	3–10 ms	10 ms	1 ms
IOPS/TPS	10,000 for a single file system	Tens of millions	33,000 for a single disk
Bandwidth	GB/s	TB/s	MB/s
Data sharing	Supported	Supported	Supported
Remote access	Supported	Supported	Not supported
Online editing	Supported	Not supported	Supported
Used independently	Supported	Supported	Not supported