Serial storage architecture
Serial Storage Architecture (SSA) describes a method for high-performance coupling of storage subsystems (i.e. mass storage devices such as jukeboxes and disk arrays) to computers, in particular to server systems or large computers. SSA is an outdated standard and was mainly used on systems from IBM .
SSA is a serial point-to-point connection via two write and two read channels. Many of the ideas from SSA have been incorporated into the more modern S-ATA standards and, in particular, Serial Attached SCSI (SAS) . SSA is compatible with the SCSI instruction set.
For its time, SSA had a very good data throughput of up to 160 MB / s. This was achieved through multiple parallel I / O processing in full duplex mode .
SSA was (and still is) used primarily in the IBM 7133 Disc Subsystem. It was initially able to be expanded to a total capacity of 582 GB in a tower. Modern hard drives mean that a maximum capacity of up to 2.34 TB per tower and a total of up to 14.0 TB per host adapter is possible. The IBM 7133 is highly available and can mirror data up to 10 km away with an optical SSA extender. The system allows disk sharing by connecting multiple UNIX, Windows NT and Novell NetWare hosts at the same time. Because of this impressive performance data, IBM 7133 systems can still be found in data centers today.