Hi All,
My question was :
> We're planning a migration from VMS to DU
> We've several alpha cpu on the lan.
>
> if you knows what CI and HSC are, and what Digital partnumber it refers ...
here're the answers to my question about HSC an CI.
CI stands for "Computer Interconnect". It's a Digital proprietary high
speed LAN (really a star network) that was originally implemented on the
DECSYSTEM-20 line of computer systems, and at about the same time on the VAX
family (with the CI780 on the VAX 11/780, the CI20 on the KL20 models, and
subsequent CI implementations to interface to the I/O backplane on various
later system models). The part number depends on the system model that is
being connected to the star, but it typically will start with "CI".
HSC stands for "Hierarchical Storage Controller" which is a microcomputer
based storage subsystem that connects to the CI and manages one or more
disks or tape drives. The first implementation of the HSC was the HSC50
which was based on the PDP-11 (I think it was the F11 chip, but it might
have been the J11). There were a number of later models. As far as I know
all of the HSC versions had model numbers beginning with "HSC".
These components are at the heart of VMS cluster software implementation,
at least, if you want good performance and high availability.
I believe that Digital UNIX supports some variation of the HSC controllers
on some variation of the Alpha systems (probably the DEC 7000), but I don't
know for certain. I'd have to dig out back copies of the Systems and
Options Catalog and look to see what was marketed. If we support the CI we
almost certainly also support the HSC, but not the same way OpenVMS supports
it (no clustering for Digital UNIX yet, and when it happens it will use a
different system interconnect technology than the CI).
_________________________________________
CI - Computer Interconnect. It is a high speed serial
bus (by 1970 standards), supporting a maximum bandwidth
of 70 mb/sec (megabites). There were various CI adapters
for VAX systems and DECsystems over the years:
An SBI CI adapter for the VAX 11/780 and VAX 8600.
A CI adapter for the VAX 11/750 which was adapted
to work on the early VAX 8200 series.
A native VAXBI CI adapter for the VAX 8200 family
and VAX 8500/8700/8800 family. These were also
used on the early VAX 6000 family. There may
have been two native VAXBI CI adapters, but I
don't recall.
A native XMI CI adapter for the VAX 6000, VAX 9000
and VAX 7000 family.
A native TURBOchannel CI adapter used on the DECsystem
5900.
Host CI connections went to a passive connection device
called a Star Coupler. This provided a star network
configuration for all the hosts on the CI. ULTRIX
eventually implemented networking code to use the CI
as a network connection. However, it was mainly used
as a storage connection by allowing...
HSC - Hierarchial Storage Controller. One of a family
of multi-disk disk/tape subsystems which used also used
the CI adapter for host communication. A typical VAX-
cluster (later VMScluster) was two or more hosts and
one or more HSCs on a common Star Coupler. The hosts
could communicate directly over the CI, and the HSC
provided equal access to its connected disks.
The HSC provided Mass Storage Control Protocol (MSCP) and
Tape MSCP (TMSCP) service to connected hosts. This was a
storage protocol similar to SCSI, but predating it. In
the HSC MSCP/TMSCP commands would be accepted, decoded and
optimized to offer the best through-put. The HSC would
do seek ordering, command fragmentation, etc. The commands
would also be protocol converted for the devices served by
the HSC. Typically this was the RA and TA family SDI disks
and tapes, but in recent years support for SCSI adapters
has been added.
The general CPU of the HSC was a microprocessor version of
the PDP11 family. I think the HSC50, the first model in the
family used the F11. The HSC70, used the J11, which was
faster. The HSC60 and HSC90 used an even faster version
of the CPU and included support for a read cache. I/O
connections were provided by a variety of modules:
K.sdi - 4 port MSCP disk controller
K.sti - 4 port TMSCP tape controller
K.si - 4 port MSCP/TMSCP disk/tape controller
K.si8 - 8 port MSCP disk controller
K.scsi - SCSI bus adapter.
The different models of HSC supported different number of
these controllers, in turn support different number of
disks and tapes:
HSC40 - 12 disks/tapes.
HSC50 - 24 disks/tapes.
HSC70 - 32 disks or combination of disks/tapes with
up to 12 tapes.
HSC60 - Faster version of the HSC40 supporting
the K.si8 for up to 20 disks.
HSC90 - Faster CPU than the HSC70 and support up
to 48 disks.
HSC60 - Faster version of the HSC60
HSC95 - Faster version of the HSC90
Digital UNIX (formerly DEC OSF/1) for the CI/HSC family
is somewhat limited. Only the native XMI CI adapter is
supported on the DEC 7000, DEC 10000 and XMI equiped
versions of the 8400. The whole line of HSCs is supported,
but not use of the K.scsi. Thus, only RA and TA tapes
drives are supported.
I don't think the network support of the CI was preserved
going from ULTRIX to OSF/1. While ULTRIX had limited support
for multi-host disk access (to read only disks) this support
has not been extended to Digital UNIX. It may still work,
but is untested and in taking advantage of it, you do so
at your own risk.
____________________________________________
Special thank's to :
alan_at_nabeth.cxo.dec.com : Alan
phil_at_wolf.ncat.edu : Phil Krause
tpb_at_zk3.dec.com : Tom, Dr. Thomas P. Blinn
Thank's again for all your help.
bye.
Laurent Flamand Ecole Centrale de Lille.
Received on Wed Jan 17 1996 - 08:31:32 NZDT