Direct-Attached Storage (DAS) of the open system has been used for nearly 40 years. Issues such as disaster recovery have increasingly plagued system
administrators
.
The connection channel between the direct-attached storage and the server host usually adopts SCSI connection. Become an IO bottleneck; the server host SCSI ID resources are limited, and the SCSI channel connections that can be established are limited.
Direct-attached Storage
Direct-attached storage relies on the server
.
The host operating system performs data IO read and write and storage maintenance management.
Data backup
and recovery require server host resources (including CPU, system IO, etc.), and the data flow needs to flow back to the host and then to the
tape Computer
(library), data backup usually occupies 20-30% of server host resources, so many enterprise users' daily data backup is often performed late at night or when the business system is not busy, so as not to affect the operation of the normal business system. The larger the amount of data in direct-attached storage, the longer the backup and recovery time, and the greater the dependence and impact on server hardware.
The connection between the direct-attached storage and the server host usually adopts
SCSI
connection, and the bandwidth is 10MB/s, 20MB/s, 40MB/s, 80MB/s, etc. As the processing power of the server
CPU
becomes stronger and stronger, the storage hard disk space As the array grows, the number of hard disks in the array increases, and the SCSI channel will become an IO bottleneck; the server host has limited SCSI ID resources, and the number of SCSI channel connections that can be established is limited.
Regardless of the direct-attached storage or the expansion of the server host, the expansion from one server to a cluster composed of multiple servers,
or
the expansion of the storage array capacity, will cause the downtime of the business system, which will bring economic losses to the enterprise. This is unacceptable for critical business systems that provide 24/7 services in industries such as banking, telecommunications, and media. In addition, the upgrade and expansion of direct-attached storage or server host can only be provided by the original equipment manufacturer, which is often restricted by the original equipment manufacturer.