trinity-users@lists.pearsoncomputing.net

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Month: August 2018

Re: [trinity-users] stretch problems

From: Gene Heskett <gheskett@...>
Date: Tue, 21 Aug 2018 13:10:13 -0400
On Tuesday 21 August 2018 10:56:56 Felix Miata wrote:

> Gene Heskett composed on 2018-08-21 09:08 (UTC-0400):
> >> > Now that's a gotcha I did not know. How did it come that this was
> >> > thought of beeing a good idea?
> >>
> >> Yep. Exactly my thought when i spent 3-hours with a server refusing
> >> to boot after migration to a new hdd (i used a stretch flash to
> >> copy). Who the fuck toughs it was a good idea?!! Why not call it
> >> ext5 or ext4a or whatever?!!
> >
> > +100
> >
> > Now the question of the day is how the hell do we fix it?
>
> As I implied 24 hours ago in this thread, it doesn't need fixing.
> Jessie came in between Wheezy and Stretch, a long time (two years?).
> There are multiple workarounds for those who skipped over Jessie:
>
With all due respect, and thats quite a bit for you Felix, there is but 
one Jessie install here that runs Linuxcnc, and its on a raspi so we're 
downloading a sd image and the install is writing the card and plugging 
it in. I tried the installer on x86 machines and failed quite a few 
times on several different machines. The LCNC folks never did issue a 
dvd image of jessie that ran LinuxCNC.  Now they have an experimental 
stretch amd64 image that I'm playing with now, but IMO that installer is 
broken too, no way to shut the speech-dispatcher up short of turning off 
the audio amp.  Had there ever been a working amd64 or even a 32 bit x86 
jessie dvd image I would probably be running it on 6 machines here. That 
one jessie I have, running most of a ton of a 70 yo old Sheldon lathe 
from an rpi-3b, is dead stable from local power outage to local power 
outage. Too bad it never got a working installer for amd64.
 
> 1-Format the installation target using Wheezy or Jessie or old Knoppix
> or old anything in advance of starting the installer. Formatting is an
> /optional/ part of the installation process (as is partitioning).
>
BTDT, the installer can't bypass it anyway.  It it can, how?

> 2-As Dan wrote, use EXT3 instead of EXT4 (EXT3 can be converted to
> EXT4 later if desired. AFAIK, the incompatible options will not
> automatically be added on conversion.)
>
> 3-Format with the Stretch installer, but specify to omit the
> incompatible EXT4 options. I don't which it/they are, but my guess is
> the only one that is needed is "-O '^64bit'". All my Wheezys were
> eliminated around the time its support termination was announced, so
> no practical way here to test.

So theres no lifeboat left in the wild. :(
>
> 4-Use XFS instead of EXT4.
>
> 5-Use a newer and/or custom kernel in Wheezy.
> http://ftp5.gwdg.de/pub/linux/debian/debian/pool/main/l/

I downloaded one of the amd64-4.18 kernels, but since this system is a 32 
bit system, it likely won't install. One of the reasons I wanted to 
update was to get into 64 bit, but LCNC up until about a year ago, was a 
32 bit app only because the latency went to hell with 64 bits, the 
context switch frame to service an interrupt was that much bigger.

But now nearly everyone including me has exported the realtime stuff to 
fpga cards which in some simpler cases become sub $100 expenditures 
instead of trying to pour all that data back and forth over an epp 
parport, latency is somewhat less important than formerly. Now its a 
balancing act between machine max speed and adequate control, usually in 
1 millisecond windows.

Thanks Felix.

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>