Multi-sort mass storage device announcing its active paths without deactivating its ports in a network architecture

Claims

What is claimed is:

1. A data processing system comprising:

a plurality of main processing units;

a mass storage device;

a plurality of device controllers connected to said mass storage device to provide interfaces between said mass storage device and said plurality of main processing units; and

a data communications link external to said mass storage device interconnecting said plurality of main processing units and said plurality of device controllers in a network configuration; wherein:

said mass storage device includes at least two simultaneously operable means for communicating with said controllers, a first one of said at least two simultaneously operable means connecting said mass storage device to a first one of said plurality of controllers, and a second one of said at least two simultaneously operable means connecting said mass storage device to a second one of said plurality of controllers, said at least two simultaneously operable means and said network in combination providing a plurality of paths which support simultaneous communications between said mass storage device and said plurality of main processing units on different ones of said paths, and at least two paths which support communication between said mass storage device and a particular main processing unit, said data processing system further comprising:

means for allowing said mass storage device to announce to a main processing unit to which it has at least two paths, the availability of said at least two paths, without disabling any of said at least two paths.

2. The data processing system of claim 1 comprising a plurality of mass storage devices.

3. The data processing system of claim 1 wherein said mass storage device includes a plurality of disk drives.

4. The data processing system of claim 1 wherein said mass storage device includes a plurality of floppy disk drives.

5. The data processing system of claim 1 wherein said mass storage device includes a plurality of optical disk drives.

6. The data processing system of claim 1 wherein said mass storage device includes a plurality of tape drives.

7. The data processing system of claim 1 wherein said mass storage device comprises a cache memory.

8. The data processing system of claim 1 wherein said mass storage device includes a set of storage devices interconnected to operate together as a storage unit.

9. A data processing system comprising:

a plurality of main processing units;

mass storage means characterized as a mass storage unit;

a plurality of device controllers connected to said mass storage unit to provide interfaces between said mass storage unit and said plurality of main processing units; and

a data communication link external to said mass storage unit interconnecting said plurality of main processing units and said plurality of device controllers in a network configuration; wherein:

said mass storage unit includes at least two simultaneously operable ports by which said mass storage unit communications with said controllers, a first one of said at least two simultaneously operable ports connecting said mass storage unit to a first one of said plurality of controllers, and a second one of said at least two simultaneously operable ports connecting said mass storage unit to a second one of said plurality of controllers, said at least two simultaneously operable ports and said network in combination providing a plurality of paths which support simultaneous communications between said mass storage unit and said plurality of main processing units on different ones of said paths, and at least two paths which support communications between said mass storage unit and a particular main processing unit, said data processing system further comprising:

means for allowing said mass storage unit to announce to a main processing unit to which it has at least two paths, the availability f said at least two paths, without disabling any of said at least two paths.

10. The data processing system of claim 9 wherein said mass storage means includes a set of storage devices interconnected to operate together as a mass storage unit.

11. The data processing system of claim 10 wherein said set of storage devices includes a plurality of disk drives.

12. The data processing system of claim 10 wherein said set of storage devices includes a plurality of floppy disk drives.

13. The data processing system of claim 10 wherein said set of storage devices includes a plurality of optical disk drives.

14. The data processing system of claim 10 wherein said set of storage devices includes a plurality of tape drives.

15. For use in a data processing system comprising

a plurality of main processing units,

a mass storage device,

a plurality of device controllers connected to said mass storage device to provide interfaces between said mass storage device and said plurality of main processing units, and

a data communications link external to said mass storage device interconnecting said plurality of main processing units and said plurality of device controllers in a network configuration, wherein

said mass storage device includes at least two simultaneously operable means for communicating with said controllers, a data processing method comprising:

connecting said mass storage device to a first one of said plurality of controllers through a first one of said at least two simultaneously operable means and to a second one of said plurality of controllers through a second one of said at least two simultaneously operable means so that said at least two simultaneously operable means and said network in combination provide a plurality of paths which support simultaneous communications between said mass storage device and said plurality of main processing units on different ones of said paths, and at least two paths which support communication between said mass storage device and a particular main processing unit; and

allowing said mass storage device to announce to a main processing unit to which it has at least two paths, the availability of said at least two paths, without disabling any of said at least two paths.

16. For use in a data processing system comprising:

a plurality of main processing units,

mass storage means characterized as a mass storage unit,

a plurality of device controllers connected to said mass storage unit to provide interfaces between said mass storage unit and said plurality of main processing units, and

a data communications link external to said mass storage unit interconnecting said plurality of main processing units and said plurality of device controllers in a network configuration, wherein

said mass storage unit includes at least two simultaneously operable ports by which said mass storage unit communicates with said controllers, a data processing method comprising:

connecting said mass storage unit to a first one of said plurality of controllers through a first one of said at least two simultaneously operable ports and to a second one of said plurality of controllers through a second one of said at least two simultaneously operable ports so that said at least two simultaneously operable ports and said network in combination provide a plurality of paths which support simultaneous communications between said mass storage unit and said plurality of main processing units on different ones of said paths, and at least two paths which support communication between said mass storage unit and a particular main processing unit; and

allowing said mass storage unit to announce to a main processing unit to which it has at least two paths, the availability of said at least two paths, without disabling any of said at least two paths.