net.digest

Net.digest summarizes significant discussions on the HP 3000-L Internet mailing list. The column is edited by longtime HP 3000 columnist John Burke, who provides commentary on HP 3000 issues. Advice is provided on a best effort, Good Samaritan basis. Test these concepts for yourself before applying them on your systems.

Analysis by John Burke

Another good reason for user volumes
Last December and January there was a thread on the list about moving from a 5.0 to a 5.5 box. There was also a discussion about whether user volumes could be physically moved from one system to another without a RESTORE. These threads were never really completed and since I just went through this very scenario, I thought I would share my experiences.

The plan: Upgrade from a 967 on MPE/iX 5.0 to a 969KS220 pre-configured with MPE/iX 5.5, moving all the peripherals (including all the disk drives except LDEV 1) to the 969 and adding a few new disk drives in the process. The 967 has two user volume sets (10Gb and 14Gb).

Warning: HP has a checklist for moving from a 4.0 system to a 5.0 system that relies on BULDACCT to transfer the accounting structure. Do NOT use this if you are moving from 5.0 to 5.5. As I noted in one of my articles on MPE/iX 5.5, the version of BULDACCT on most 5.0 systems does not handle HFS directories correctly. I'm told by the RC that this has been corrected, but you may still have an incorrect version. And while BULDACCT is nice for documenting your account structure, the DIRECTORY option of STORE and RESTORE is easier and faster.

Here is a shortened version of the revised checklist (you need to work closely with the CE doing the install):

(if you've purchased additional new drives, do not configure them with VOLUTIL yet)

separately (be sure to use the DIRECTORY option on all your STOREs);


RESTORE *T;@.@.@;KEEP;OLDDATE;SHOW=OFFLINE;FILES=n;DIRECTORY


SYSSTART.PUB.SYS
NMCONFIG.PUB.SYS
COMMAND.PUB.SYS (udc configuration)


The OS requires some files, for example SYSSTART, be on LDEV 1;

path for the LANIC, if necessary, and make any other necessary NMMGR configuration changes. Validate NETXPORT and DTS/LINK, which should automatically cross validate with SYSGEN.


The only problem we had was that our DTCs, all managed by OpenView DTC Manager, could not "see" the new box. Since both VT and NS worked, we figured it was a hardware address problem that would be solved by resetting all the DTCs. But that would hose all the users accessing other hosts. So we called the Response Center. The text of the response from the RC:

"It sounds as if the DTC still has the HP 3000 nodename resolved to the hardware LAN address of the old system. There are three ways to clear the memory (cache) of the DTC:

1. Reset the DTC through OV DTCMGR (interrupts all users on the DTC). 2. Power cycle the DTC (interrupts all users on the DTC). 3. At a DTC> prompt, type in 'c nodename -d'

Option three will not interrupt any DTC users. The '-d' option causes the DTC to flush its cache table of nodenames to LAN addresses. Once this is done, the DTC will re resolve the name of the host to a LAN address."

This solution worked like a charm, did not impact any other users and is already filed away in my bag of tricks for future use.

Had we planned better, the whole switch, not including backup time but including the time to RESTORE the system volume set, could have been accomplished easily in under four hours.

A good reason to dabble with Unix
This was a little off-topic for HP3000-L, but I found it interesting and believe it deserves wider exposure. The thread started with the following question:

"I have a very small and very inexpensive network. I would like to add to this my dial-up ISDN connection to my ISP. At the moment, the connection is available only on a single PC. I want the connection to be available to other PCs on the network. I am looking for a piece of software that will run as a router under Win 3.1 so that I can connect my network to my ISP. Obviously I'm going to have to add TCP/IP to my PCs. Actually, I suspect I may need something a little more involved (a gateway?), because my fixed IP address is part of my ISP's network and it may cost me a lot more to get multiple IP addresses.

Chris Bartram of 3k Associates was the first to reply:

"Linux does this nicely. The standard distributions include PPP and will do routing and even firewalling. Linux will run on a 386 or better box and supports most standard hardware. Set up a 386/486 box with a 200+Mb hard drive, floppy, CD (slow is fine), an NE2000 compatible network card (clones can be bought for about $25 new), keyboard, cheap monitor (b/w is fine), and a couple serial/parallel ports. You'll probably want to be sure to have a high-speed serial port so it'll support ISDN speeds.

"Head to a bookstore and pick up a Linux book with a software distribution CD attached.

"You may need your own network address -- you need to get that from your ISP. They will likely charge you more for routing an entire network versus a single station, too."

And Bruce Toback of OPT added, "Linux includes IP masquerading, a feature that allows a network to 'hide behind' a single IP address. By using this feature, your ISP does not have to do anything at all, or even know about your arrangement. Linux will use the dynamically assigned IP address from the ISP. The only downside is that you won't be able to run something that requires that the outside world know about a fixed IP address -- like a Web server. Almost everything else will work fine.

"We used this arrangement for about six months before getting our dedicated connection. It's even handy with a dedicated connection since the Linux box can act as a firewall, making your internal network inaccessible to an attacker. Most ISPs won't assign more than a few IP addresses, so a masquerading arrangement can help you live within those addressing restrictions."

Has something really, really nice
been slipped into Express-2?
Gavin Scott noted the following upon reading the MPE/iX 5.5 Express 2 Communicator (Note: this release was scheduled to be available by the end of May):

"Modems on the 3000 have been a pain since the MPE/VE terminal I/O rewrite that prevented a program from opening a port unless the attached modem was indicating Carrier Detect. This made it impossible to setup a modem that could be used simultaneously for the following purposes:

"I have in front of me the 'Communicator 3000 MPE/iX-Express 2 (PowerPatch Tape C.55.02) Based on Release 5.5' manual that came in the mail the other day. On page 2-11, under 'New Functionality Supported in DTS/TIO', under 'New Features', it says:

'Three new modem types for attached device. The new modem types are US modem In Out, European modem In Out, and five wires modem.'

"Can this be what it sounds like? There is no further explanation of what these new modem types actually do, other than a mention that they are only supported on the DTC 72MX, DTC 16iX, and DTC 16MX."

What will you give for a slightly used
copy of OpenView DTC Manager?
Based upon comments made on 3000-L over the last several years, it appears that many people employ OpenView DTC Manager primarily to enable DTC switching. DTC switching means that a terminal, or PC emulating a terminal, connected to a "switchable" DTC can use the CONNECT command to "connect" to any host "known" to the DTC. Obviously a useful feature in any multi-server environment. OpenView DTC Manager requires a PC that is essentially dedicated, which often becomes the weak link in the network. One of the less well publicized goodies that came with MPE/iX 5.5 is host-based DTC switching. A heavily edited version of the latest thread follows:

"Is it possible to configure a DTC 48 or DTC 72 to allow access to multiple HP 3000s? I've heard that I can do this with HP OpenView DTC Manager. I don't have OV DTC Manager and will only have the two 3000s for a short period of time. Is there any other possible solution?"

"We have not found any way to do this without OV DTC Manager. With MPE/iX 5.5 you can do dynamic DTC configuration changes without rebooting, but you still can't enable a DTC port as switchable without DTC Manager. If we could use NMMGR to enable switching on a DTC port, we'd probably ditch DTC Manager in a heartbeat. For your short-term scenario there may be another way to handle it. If the machines have the full NS Services installed you can :REMOTE HELLO from one HP 3000 to another, or if you have MPE/iX 5.5 you can telnet from one to the other."

"You can do this enable switching with either OpenView DTC Manager or host based with MPE/iX 5.5. You get a DTC prompt and 'connect' to whatever specified host you wish. It works great. We use it to share 15 DTCs (48's and 16/MX's) to three different 3000s. I believe the only DTC that does not support this is the 16/iX."

"How do you do this? I'm on 5.5 and I've been all through the NMMGR screens and haven't found any reference to an 'enable switching' flag. We use DTC48's."

"As I remember, only the 'newer' DTC48's can do host switching -- the older ones need the 'memory upgrade' to hold the code for the switching version of the DTC image."

"A new function key called 'Go to Switch' appears for host-based profiles on MPE/iX 5.5. The screen that comes up contains the switching configuration. You must turn off (N) the flag for 'Are you using OpenView DTC Manager?' for the magic function key to be revealed. I recommend you check out the 5.5 edition of 'Configuring Systems for Terminals, Printers, and Other Serial Devices', P/N 32022-61000. It is also on LaserROM."

"As soon as I can get my configurations synchronized, we will be dumping DTC Manager for good! Thanks to HP for simplifying my life a little bit. NMMGR is still a beast of a program with mind-numbing layers upon layers of screens, but at least now I don't have to rely on a flaky PC program to keep my DTCs in line. And I can go back to using TERMDSM, so I won't have to run to the PC in the machine room any more just to do a port reset."


Copyright 1997, The 3000 NewsWire. All rights reserved.