List Lurkers,
So typeth the Troth, or with a quick vowel change...
The TRUTH lieth below...
Blessings and the luck of Torvalds...
Flint,
Minister
Church of the GNU...
On Wed, 16 May 2018, Rick Troth wrote:
Date: Wed, 16 May 2018 15:14:59 -0400
From: Rick Troth <r...@casita.net>
Reply-To: Linux on 390 Port <LINUX-390@VM.MARIST.EDU>
To: LINUX-390@VM.MARIST.EDU
Subject: Re: single user mode under z/VM
On 05/16/2018 02:23 PM, Terri C. Glowaniak wrote:
Just wondering what 'console' people use to access their Linux systems
when using 'single user mode' ... 3270, IUCV, or ?
"yes"
*IUCV* is best, if you have an IUCV terminal server running. You can SSH
into the terminal server, hop to the ailing Linux guests via IUCV, and
"everything is normal". (Well ... except that you're in single-user
maint mode.) We really should make more use of IUCV in all ways,
terminal server, things layered on that, and non-terminal traffic. It's
awesome!
While I have in my time incanted with IUCV I must petition the Troth that
this potent VM Magic (VMM) may not be the best for an initiate. A wizard
of your standing can hold power over the wild IUCV, transfer files, edit
minidisk content, run DDT (whose name will be spoken here), or invoke new
CMS, but I plea, this is a dangerous path!
*3215* (which might be what you mean by "3270") is tolerable if you're
okay with a truly line-mode environment. It really confuses some
Unix/Linux people who have never used serial line consoles and such.
It's not difficult, just tedious. This is *#CP CONMODE 3215* and is the
default we all know and love.
True *3270* would be fine, but would give you the same operation as
3215, except Linux is translating 3270 interaction into line-at-a-time.
(And there is no 3215 because that only applies when z/VM is doing this
hack.) The upside is that you *can* run some full-screen apps. They'll
display like they're on an XTERM or similar ANSI X3.64 screen. You just
don't get byte-at-a-time /input/, which almost all of them kinda of
expect. Careful with what mode you're in when using 'vi', for example.
And don't even think about using EMACS. You'd simply need the 3270
driver and *#CP CONMODE 3270*. Works.
My heresy is to recommend a Linux based workstation and the use of X3270,
while blessed with good defaults it's only sin seems to be endless command
line configuration options... one of which is to run as a monochrome
console similar to the 3215... presuming I got my terminal model number
correct. IBM doctrine often refers to the "3270" implementation of the
blessed SNA terminal protocol. Troth is far more realistic. 3270 is, as
far as I can tell, very similar to the VT100 mode of the Dearly Departed
Digital Equipment Corporation. Hardware that lives on in software...
If you're on bare metal, you can use *SYSASCII*. Never done that. (Wish
z/VM would support it for remote access.)
Me neither, we live in an age of miracles!
Another option is to have a *rescue system* available in a pinch, so you
can sign-on to the ailing Linux guest, bring up the rescue environment,
get it onto the network, and then SSH like normal.
Another option is to attach the *minidisks* of the ailing guest to a
*different Linux guest*. Mount it/them, 'chroot', and do what needs doin.
Even if it means setting up a separate bare bones image, this is a great
idea that I also have been pushing. Terri, it may take some time and
skill acquisition to get a stable zLinux image on this obviously
mis-configured system you have been blessed with. Personally, at times
like this I take my hands off the keyboard, place them together, and bless
the fact that I am being paid by the hour...
Strategically, the One great Truth (or Troth:^) is to "swing through
success". Get some image booting some version of zLinux. I would bear
witness to the fact that The Wizard Troth has a few secrets up his sleeve
in this area of lean/mean images.
I don't know if this helps, but it's fun ... FSVO "fun".
-- R; <><
☮ Paul Flint
(802) 479-2360 Home
(802) 595-9365 Cell
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