kemp@uiatma.atmos.uiuc.edu (John Kemp) (03/15/91)
I am trying to bunk or debunk a couple of myths about
HP clusters.
1) Can devices on a cluster client be accessed by the
cluster server? (If not, hanging peripherals off of
clients would be fairly exclusive.)
2) Is a second network card really necessary on the server?
(The manuals say "yes". Other people say "no".)
If there is a better source of documentation about
HP clusters somewhere, it would be nice to know about.
The Sys Admin manuals tend to be a bit weak in this area.
Thanks in advance,
-------- john kemp ( ( )_ internet - kemp@uiatma.atmos.uiuc.edu
----- ( ( __) decnet - uiatmb::kemp
--- univ of illinois (_ ( __) bitnet - {uunet,convex}
-- dept of atmos sci .(____). !uiucuxc!uiatma!kemp
- 105 s gregory ave ... phone - (217) 333-6881
- urbana, il 61801 ... fax - (217) 444-4393gabby@gabs.lbl.gov (Gabby Obegi) (03/15/91)
In article <1991Mar14.231124.13611@ux1.cso.uiuc.edu>, kemp@uiatma.atmos.uiuc.edu (John Kemp) writes: > > I am trying to bunk or debunk a couple of myths about > HP clusters. > > 1) Can devices on a cluster client be accessed by the > cluster server? (If not, hanging peripherals off of > clients would be fairly exclusive.) If you mean a laser printer or other output devices. Yes, it's possible and reasonably easy to do. Diskless clients can have raw devices as peripherals, they can't have block devices yet. I believe that'll be in HP-UX 8.0. > > 2) Is a second network card really necessary on the server? > (The manuals say "yes". Other people say "no".) > I'm running a large network with several Cluster servers and they all have only one network card. > If there is a better source of documentation about > HP clusters somewhere, it would be nice to know about. > The Sys Admin manuals tend to be a bit weak in this area. > > Thanks in advance, > -------- john kemp ( ( )_ internet - kemp@uiatma.atmos.uiuc.edu > ----- ( ( __) decnet - uiatmb::kemp > --- univ of illinois (_ ( __) bitnet - {uunet,convex} > -- dept of atmos sci .(____). !uiucuxc!uiatma!kemp > - 105 s gregory ave ... phone - (217) 333-6881 > - urbana, il 61801 ... fax - (217) 444-4393 ============================================================================= Gabby Obegi, CAE Systems Manager Lawrence Berkeley Laboratory MS 90-2148 (415) 486-5209 1 Cyclotron Rd Fax: (415) 486-6668 Berkeley, CA. 94720 Internet: G_Obegi@LBL.gov =============================================================================
rjn@hpfcso.FC.HP.COM (Bob Niland) (03/17/91)
re: > I am trying to bunk or debunk a couple of myths about > HP clusters. > 2) Is a second network card really necessary on the server? > (The manuals say "yes". Other people say "no".) No. The idea is to keep diskless traffic off your site backbone. There are several ways to do this; one is to configure the server as a gateway machine with two lans (as mine used to be). You can also: * isolate the diskless cluster via a bridge (as our department's is now). * have some other non-server/non-client machine on the subnet be a gateway * have no site LAN, in which case the issue is moot * have a low-usage backbone, "" "" Regards, Hewlett-Packard Bob Niland Internet: rjn@FC.HP.COM 3404 East Harmony Road UUCP: [hplabs|hpfcse]!hpfcrjn!rjn Ft Collins CO 80525-9599
lanzo@wgate.UUCP (Mark Lanzo) (03/18/91)
In a prior article kemp@uiatma.atmos.uiuc.edu (John Kemp) wrote:
I am trying to bunk or debunk a couple of myths about
HP clusters.
Well, here's a couple of answers that should be good bunk :-)
Seriously, a little more info is really needed here. What type
of cluster? What revision OS? The answers here are based on
HP9000/S-300 clusters with HP-UX 7.0B.
Disclaimer: answers are based on my own experience; any advice or
information to the contrary would be greatly appreciated.
On with the show....
1) Can devices on a cluster client be accessed by the
cluster server? (If not, hanging peripherals off of
clients would be fairly exclusive.)
No -- unless you consider remote-login to the root server as "accessed by".
You can hang peripherals off of other nodes (for instance, our printer
is on one of our diskless nodes), but you cannot mount filesystems
locally.
Access to devices on remote nodes seems to only work by having
a process actually running on the remote node which communicates with
your local process. Of course, in some sense this is always true
when sharing devices with foreign systems, what I mean here is that
this sharing is not transparent or automatic. I am not referring to
file or device sharing protocols (like NFS, RFS, etc). What I mean is
that programs like "uucico" turn out to be cnode specific files which
are actually stub programs -- these stubs run a server specific version
of the program on the server and set up communications with it.
Sometimes this is a big problem. For instance, we wanted to set up UUCP
connections over our phone line, and also needed a printer. HP doesn't
support this -- both the UUCP and printer software want to run on the
server -- and there's only one serial port. Buying an extra serial port
card for the server is not what I would regard as an acceptable solution,
given that we had plenty of free serial ports available from all of the
diskless nodes. Fortunately in this case it wasn't very difficult to
con the system into running the "lp" scheduler on one of the diskless nodes.
On the other hand, we never did succeed in getting UUCP to work from a
cnode.
2) Is a second network card really necessary on the server?
(The manuals say "yes". Other people say "no".)
No. We have a bunch of workstations here, divided into a couple of
clusters. None has more than one ethernet port.
If there is a better source of documentation about
HP clusters somewhere, it would be nice to know about.
The Sys Admin manuals tend to be a bit weak in this area.
Yup. The only thing I know of is the "HP-UX Clusters" chapter
in the "HP-UX System Administration Concepts" book.