Difference between revisions of "Hierarchical Storage Controller"
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== HSC Overview == | == HSC Overview == | ||
| − | The '''Hierarchical Storage Controllers''' ('''HSC''') were a series of stand-alone, intelligent | + | 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]] (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.) | 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.) | ||
| Line 15: | Line 15: | ||
* 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) | + | * [[Small Computer System Interface|SCSI]] data channel (optional on HSC70 and later models) |
Several different HSC models were produced: | Several different HSC models were produced: | ||
| Line 26: | Line 26: | ||
* HSC90 | * HSC90 | ||
* HSC95 | * HSC95 | ||
| + | |||
| + | A number of adapters are available, to connect SCSI devices to the various [[bus]]es used by HSC systems: | ||
| + | |||
| + | * [[HSD10 DSSI-to-SCSI Bus Adapter]] | ||
| + | * [[HSG60 FC-to-SCSI Bus Adapter]] | ||
| + | * [[HSJ30 CI-to-SCSI Bus Adapter]] | ||
== HSC Software == | == HSC Software == | ||
Revision as of 23:22, 12 January 2024
HSC Overview
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:
A number of adapters are available, to connect SCSI devices to the various buses used by HSC systems:
HSC Software
The HSCs needed a special software (kind of an operating system) to run, the official software name was HSC (same as the hardware), the project name, CRONIC (Colorado Rudimentary Operating Nucleus for Intelligent Controllers), was sometimes used instead.
The HSC software was distributed on TU58 tape cartridges for the HSC50 and on RX33 floppy disks for all other HSC models.
The time to boot an HSC varied with the boot device; the TU58 took more than 6 minutes, the RX33 less than one and a half minute.
Further reading
- HSC User Guide (AA-GMEAA-TK) - not online
External links
- HSC - documentation at Bitsavers
- HSC Controller Installation Manual (EK-HSCMN-IN-002)
- VAXcluster Maintenance Student Workbook: Volume 2 (EY-9222E-SB-0001) - this volume is dedicated to the HSC
- The Hierarchical Storage Controller, A Tightly Coupled Multiprocessor as Storage Server - in Digital Technical Journal, Volume 1, Number 8 (February 1989); on pp. 10-26 of the PDF
