dww@stl.UUCP (David Wright) (07/11/85)
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Does anyone have any experience with SI's SIMACS product, especially on
VAX VMS v4?
We have used SI Tape and Disk systems on our VAXes for 2-3 years now. In
general we have found them faster, cheaper and more reliable than DEC's -
for example we think the 400Mbyte 'Eagle' disks are great, and like being able
to run them on a CMI interface ('750 Massbus) instead of overloading the Unibus
as the DEC RA80/81 tend to do. We've had the odd problem, but have been
impressed with the effort and helpful attitude shown by SI in fixing these.
I note that others feel the same - e.g. ukc (a UK UUCP 'backbone' site)
recently announced that it was throwing out it's DEC RA81's in favour of SI
Eagles on reliability grounds.
BUT now we have bought SIMACS. We want to 'cluster' 3 VAX-750's (under VMS),
but cannot afford DEC prices. SIMACS is a disk-sharing system that ought
to give much of the benefit of the DEC Cluster in a simpler - and therefor much
cheaper - way, especially for sites like ours which already have a lot of SI
kit. Originally SIMACS would not support sharing on the system disk, but we
were assured by the SI sales people that this was now solved. We could not
have shared job queues just by sharing disk files but we can live without them.
What we do want to do is have an identical environment to the user regardless
of which of the three VAXes he/she logs in on - so we need to share SYSUAF.DAT
and VMSMAIL.DAT (the V4 system mail file), for example.
When SIMACS was installed, nothing worked. We couldn't boot a shared system
disk, and when we 'un-shared' that we had problems with mail until we removed
SI's patches to the MAIL program, and problems with access to the shared user
disk. Access Contol Lists are no longer supported, SET VERIFY doesn't work
(apparently a DEC SW problem with the BR ACP??), etc. It seems that although
the system works well on VMS V3, and we were assured all would be well on V4
(we're running 4.1), proper support for V4 is still some way off. We have our
system back up and running (using a disk ACP as SIMACS does not use the full V4
filer yet), but without being able to go over to a fully shared system yet.
If they follow past form, SI should fix these problems OK. But the problems
seem more serious than we would expect, and we are beginning to wonder how
many sites are running SIMACS with v4 - we cannot be the first, surely?
If you have experience running SIMACS under VMS V4.x, or know about a site
that does, please mail me (or 'phone on +44 279 29531 ext 3697). Thanks.