Lenovo Group has agreed to buy IBM's x86 server hardware business and related maintenance services for $2.3 billion, it announced Thursday. The deal encompasses IBM's System x, BladeCenter, and Flex System blade servers and switches; x86-based Flex integrated systems; NeXtScale and iDataPlex servers and associated software; blade networking and maintenance operations. IBM will retain its System z mainframes, Power Systems, Storage Systems, Power-based Flex servers, and PureApplication and PureData appliances.