Dense server environment that shares an IDE drive

#The present invention relates to the field of a dense server environment, and more particularly to a dense server environment that allows a shared Integrated Drive Electronics (IDE) fixed disk drive to be accessed by multiple server blades.

#In a dense server environment, multiple computer systems commonly referred to as server blades may each have the ability to access a shared device over a network, e.g., Local Area Network (LAN). A server blade may refer to a typical server that does not include a mass storage unit, e.g., fixed disk drive. The storage unit, e.g., fixed disk drive, may be the shared device that each server blade has the ability to access. Typically these storage units are standard Small Computer System Interface (SCSI) drives which use a significant amount of power and space. Hence it would be desirable for the shared storage device to be a drive as small as possible thereby not using a significant amount of power or space.

#One particular drive that is small in size and uses a relatively low amount of power is an Integrated Device Electronics (IDE) drive. An IDE drive refers to a drive where controller electronics are built inside the drive. Furthermore, IDE drives are drives that cannot be accessed by multiple devices or multiple programs within a server because there does not exist a suitable protocol that allows multiplexed accesses. Since IDE drives cannot be accessed in a multiplexed fashion, IDE drives may not be accessed by multiple server blades in a server blade environment.

#A better understanding of the present invention can be obtained when the following detailed description is considered in conjunction with the following drawings, in which:

#FIG. 1 illustrates a dense server environment configured in accordance with the present invention;

#FIG. 2 illustrates a memory space for a controller in the dense server environment configured in accordance with the present invention;

#FIG. 1—Dense Server Environment

#FIG. 1 illustrates an embodiment of the present invention of a dense server environment 100. Dense server environment 100 may comprise a plurality of server blades 101A-E coupled to a bus 103, e.g., Peripheral Component Interconnect (PCI) bus. Server blades 101A-E may collectively or individually be referred to as server blades 101 or server blade 101, respectively. Dense server environment 100 may further comprise a controller 104 coupled to bus 103. Controller 104 may be configured to provide a mechanism for sharing an Integrated Device Electronics (IDE) drive 105 coupled to controller 104 among each server blade 101 as described in greater detail in conjunction with FIGS. 6A-B. Controller 104 may further be coupled to a memory 106 configured to store commands to access IDE drive 105, e.g., read from one or more logical blocks, write to one or more logical blocks, issued from server blades 101. It is noted that dense server environment 100 may comprise any number of server blades 101 and IDE drives 105 and that FIG. 1 is illustrative. It is further noted that in an alternative embodiment, dense server environment 100 may comprise multiple IDE drives 105 coupled to controller 104 through one or more channels thereby accomplishing mirroring. It is further noted that dense server environment 100 may be any type of system that has a plurality of server blades 110, a controller 104, a controller memory 106 and at least one IDE drive 105 and that FIG. 1 is not to be limited in scope to any one particular embodiment.

#Referring to FIG. 1, a server blade 101 may refer to a server that does not include a storage unit, e.g., Compact Disc Read Only Memory (CD-ROM) drive, floppy disk drive. Each server blade 101 may be configured to communicate with other server blades or with controller 104 via bus 103, e.g., PCI bus. A server blade 101 may be configured to issue requests to write to particular memory addresses in either local memories, e.g., memories in server blades 101, or in controller memory 106. The requests to write to one or more memory addresses in controller memory 106 may comprise commands, e.g., read from one or more logical blocks, write data to one or more logical blocks, to access IDE disk 105 as well as any data associated with the commands. A more detailed description of server blade 101 is provided further below in conjunction with FIG. 4.