Difference between revisions of "Hierarchical Storage Controller"
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The '''Hierarchical Storage Controllers''' ('''HSC''') were a series of stand-alone, intelligent [[mass storage]] [[device controller|controllers]], created by [[Digital Equipment Corporation|DEC]] for use in [[VAXcluster]] system. They were connected to the [[VAX]] systems in the VAXcluster over [[Computer Interconnect]] links. | The '''Hierarchical Storage Controllers''' ('''HSC''') were a series of stand-alone, intelligent [[mass storage]] [[device controller|controllers]], created by [[Digital Equipment Corporation|DEC]] for use in [[VAXcluster]] system. They were connected to the [[VAX]] systems in the VAXcluster over [[Computer Interconnect]] links. | ||
| − | An HSC supports a number of [[disk]] and [[magnetic tape]] 'data channels' - the exact number of each depends on the HSC model. Disk data channels use the [[Standard Disk Interconnect]], and can support up to four [[drive]]s on each. Tape data channels use the [[Standard Tape Interconnect]], and can support up to four [[magnetic tape controller|formatter]]s on each; the number of [[magnetic tape drive]]s per formatter will depend on the formatter. (Dual-ported drives are supported, so that each drive is accessible via two HSC's, further improving reliability.) | + | An HSC supports a number of [[disk]] and [[magnetic tape]] 'data channels' - the exact number of each depends on the HSC model. Disk data channels use the [[Standard Disk Interconnect]] (SDI), and can support up to four [[drive]]s on each. Tape data channels use the [[Standard Tape Interconnect]] (STI), and can support up to four [[magnetic tape controller|formatter]]s on each; the number of [[magnetic tape drive]]s per formatter will depend on the formatter. (Dual-ported drives are supported, so that each drive is accessible via two HSC's, further improving reliability.) |
Physically, an HSC consists of a number of [[printed circuit board|boards]] mounted in a [[card cage]] held in an [[H9642]] cabinet, along with [[power supply]] units. The drives are mounted in additional cabinets. Logically, an HSC contains: | Physically, an HSC consists of a number of [[printed circuit board|boards]] mounted in a [[card cage]] held in an [[H9642]] cabinet, along with [[power supply]] units. The drives are mounted in additional cabinets. Logically, an HSC contains: | ||
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* a control processor | * a control processor | ||
* memory | * memory | ||
| + | * cache memory (optional on HSC90 and later models) | ||
* disk data channel(s) | * disk data channel(s) | ||
* tape data channel(s) | * tape data channel(s) | ||
| + | * [[SCSI]] data channel (optional on HSC70 and later models) | ||
Several different HSC models were produced: | Several different HSC models were produced: | ||
| + | * HSC40 | ||
* HSC50 | * HSC50 | ||
* HSC60 | * HSC60 | ||
| + | * HSC65 | ||
* HSC70 | * HSC70 | ||
* HSC90 | * HSC90 | ||
| + | * HSC95 | ||
{{semi-stub}} | {{semi-stub}} | ||
Revision as of 13:52, 22 August 2022
The Hierarchical Storage Controllers (HSC) were a series of stand-alone, intelligent mass storage controllers, created by DEC for use in VAXcluster system. They were connected to the VAX systems in the VAXcluster over Computer Interconnect links.
An HSC supports a number of disk and magnetic tape 'data channels' - the exact number of each depends on the HSC model. Disk data channels use the Standard Disk Interconnect (SDI), and can support up to four drives on each. Tape data channels use the Standard Tape Interconnect (STI), and can support up to four formatters on each; the number of magnetic tape drives per formatter will depend on the formatter. (Dual-ported drives are supported, so that each drive is accessible via two HSC's, further improving reliability.)
Physically, an HSC consists of a number of boards mounted in a card cage held in an H9642 cabinet, along with power supply units. The drives are mounted in additional cabinets. Logically, an HSC contains:
- a CI interface
- port processor
- port buffer
- port link
- a control processor
- memory
- cache memory (optional on HSC90 and later models)
- disk data channel(s)
- tape data channel(s)
- SCSI data channel (optional on HSC70 and later models)
Several different HSC models were produced:
- HSC40
- HSC50
- HSC60
- HSC65
- HSC70
- HSC90
- HSC95
Further reading
- HSC User Guide (AA-GMEAA-TK) - not online
