My original question
----------------------------------------------------------
I was wondering if anyone out there had installed DS-DWZZH-03/05
UltraSCSI Hubs and whether they had any comments about their
installation, how they perform, any problems they've caused etc. I'm
particularly interested to find out whether anyone has had problems with
bus isolation when one host attached to the hub has become detached
through either a crash or scheduled downtime. Even if you're just using
them and they work fine, please reply so that I know they are in use at
other sites. A summary will follow as usual. TIA.
----------------------------------------------------------
Many thanks to the following for sharing their experiences of the
products with me:
Acacio (Casey) Carvalho - CASEY_at_YORKU.CA
Judith Reed - jreed_at_wukon.appliedtheory.com
Brian Young - byoung_at_oru.edu
Rodrigo Poblete - rpoblete_at_gmd.com.pe
I've listed their responses below so that any one else investigating
SCSI-Hubs can get an idea of what people using them think of the
product.
-------------------
>From Acacio (Casey) Carvalho
We have one 5 port SCSI hub which we use to provide storage to a Windows
NT
Server and an Alphaserver 4100 running DU 4.0B. The storage resides on
a
SW ESA10000 with HSZ70 controllers. The setup has been in place for
about 2
months, and so far we have not had problems. Both systems have gone
done, at
the same time, and at different times, due to either planned outages or
crashes.
So far, no ill effects...
P.S.: I don't know about your environment, or what you are planning to
connect
the SCSI hub to, but plan your setup. In our case, the addition of the
SCSI hub
was something that happened sometime after we bought the ESA1000 with 4
HSZ70s.
At the time field service configured the HSZ70s for best performance,
and that
meant allocating 3 (maybe 4) buses to some RAIDs on the ESA10000. When
we
bought the SCSI hub, we were still able to allocate one bus to the NT
server
storage, but now, we have no more buses available on the HSZ70s (and 2
more free
ports on the hub). The only way that we can use the current hub, is to
reconfigure the HSZ70s and free up 1 or 2 buses, but I'm told that this
will cause
a device reorganization at the O/S level, which means that we will have
to do
a backup and restore, plus redo our AdvFS and LSM setup.
---------------------
>From Judith Reed
We just completed a 2.5 hour marathon adventure with the DWZZH-05. After
having attached 3 systems to it, I rebooted one of the 3, and it began
cycling
thru scsi cam errors, took about 1.5 hours to boot. I rebooted the
second,
and the third, and they did the same. I then disconnected the cable on
the
third, at the host end, and the other two began booting cleanly. None
saw the
disks, however.
Field service came in, and began pulling connectors from the hub,
attaching
to diff. ports on the hub. It appeared that any system connected to the
left
hand ports of the hub:
=======
======= =======
======= =======
left right
saw disks but any on right didn't. We pulled cards, tried moving
switches on
the cards, detached and reattached cables. Finally, all three systems
were
attached as they had begun, all switches were as they had started, and
all
three systems saw all disks. Why??? Who knows. Not a clue.
Is this of any use? Probably not, but you asked!
--------------------------
>From Brian Young
We are using one. It seems perfectly fine. No problems.
We have rebooted one server attached to the hub multiple
times, and had no problems.
--------------------------
>From Rodrigo Poblete
I have a Three port HUB
One port to a RA700
and the two other ports to 2 KZPSAs on two Alphas 4100
DU 4.0d + PK2
They work fine...
I can disconnect any Alpha from the HUB..
And the other Machine Won't Notice....
---------------------------
Again, many thanks to those who took time to respond.
Cheers,
Sean
Sean McGlynn (TMIAU)
email smcgly_at_acxiom.co.uk
phone +44 (0)171 378 7244 x.3118
fax +44 (0)171 378 6525
Received on Tue Sep 29 1998 - 13:23:38 NZST