With expanding usage of virtualization and consolidation of computed sources utilized in blade type server has greatly increased the role of extern disc systems. Building of Storage Area Network (SAN) solutions replaces hardly manageable local disc sources.
Costumer has the option to choose from variety of disc field classes and connection technologies (FC, iSCSI, FCoE, SAS). Each class in generally defines performance, availability and scalability of disc fields.
From the disc offer there is an option to choose extremely fast SSD discs used as transaction logs of database systems. Furthermore, can be chosen fast 20 or 15 thousand turn disc type SAS/FC for applicational data. And at last slower discs Nearline SAS or SATA for data with lower requirements on fast access points.
For back-up can be opted for tape mechanics, simple autoloaders or scalable libraries(mostly DAT and LTO technologies). There has been an increased amount of virtual tape libraries with discs as back-uping medium instead of linear tapes. Great deal of importance has to be put on the choice of back-up software as well as on his virtualization support or application agents.