l1ngo@cudnvr.denver.colorado.edu (03/14/91)
Thanks to everyone who replied to my message or sent me email. Here is a
compilation of the answers which may help some of you in solving your
problems with the ram image.
I finally got it to work using a 200K ram image (as suggested by some of
these people--I was trying to use too large a ram image on my 1 Meg of ram
286).
However, also as some of you suggested, I have reverted back to using my
hard disk paritition since there's plenty of space on the HD, but not a heck
of a lot of RAM. So until I get 4 Megs of RAM, /dev/hd3 will be root..
Thanks again,
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LINH NGO University of Colorado At Denver
Amiga!// l1ngo@cudnvr.denver.colorado.edu
\X/ lngo@copper.denver.colorado.edu
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From: IN%"gwdokokl!ahrea@uokmax.ecn.uoknor.EDU" 21-FEB-1991 03:39:20.27
From: gwdokokl!ahreaDOD@uokmax.ecn.uoknor.EDU (Alan Rea)
Subject: MINIX ram disk
Hi. I have been using MINIX on two different systems. I was able to get a
360K ram drive to work on the AT clone, reading the ram image from /dev/hd3.
For my first try, I tried a 512K disk and got a message something like :
mm panic, not enough memory!
(I don't remember the exact message.) When I made the image smaller, I had no
problem. I did have the partition size set at 2Mb, but just used mkfs to make
a smaller file system on it. That worked. I've seen on comp.os.minix some
messages that indicated you can't make a ram image larger than 384K on an AT,
because of the boundary in memory at 640K, which MINIX won't cross. (It loads
the ram disk above it if it fits, below it if it doesn't.) Did you get this
panic message?
The other system I'm trying to run MINIX on is the one I'm having trouble with.
It has 4Mb of ram, but I can't use the hard drive yet because its Seagate ST01
controller is interfering with the boot process. I was trying to load as much
of the os on a 1.2Mb floppy as possible, transfer that to this system, and use
more of the ram. It wouldn't work.
What sort of problem did you have with your 512K ram image? Did you get a
memory panic error, or did it just hang, like mine did on the Amstrad? I'm
wondering if it's worth a try to make a 384K ram image and see if that works.
Maybe its not just AT's that are limited to that, although the manual clearly
advises making a ram drive of up to 2Mb...
It sounds like we're running into the same sort of problem. Lets keep in
touch and let each other know what we find... By the way, what sort of system
are you running?
Al
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Subj: RE: Problems with using /dev/hd3 as ram image
From: kjh%pollux.usc.edu@usc.EDU (Kenneth J. Hendrickson)
Newsgroups: comp.os.minix
Organization: EE-Systems, USC, Los Angeles
Since you only have 1M of memory, you should use a ram disk size of 250M
or less.
If your memory maps above FFFFF, and you have 384k up there, then you
may get away with a ram disk size of 384k.
Ram disks with sizes above ~ 250M go into extended memory. Your system
is crashing because the memory isn't there.
--
favourite oxymorons: student athlete, military justice, mercy killing
Ken Hendrickson N8DGN/6 kjh@usc.edu ...!uunet!usc!pollux!kjh
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From: IN%"dcox@magnus.ircc.ohio-state.EDU" "Dena A Cox" 7-MAR-1991
From: Dena A Cox <dcox@magnus.ircc.ohio-state.EDU>
Subject: RE: Problems with using /dev/hd3 as ram image
Newsgroups: comp.os.minix
Organization: The Ohio State University
In article <1991Mar6.145656.53@cudnvr.denver.colorado.edu> you write:
>Hello,
>
>I recently bought Minix 1.5 from Waldensoft. Everything seems to work fine
>with my Compudyne 286/16 with 2 Seagate IDE Hard drives (40 Meg, and 110
>Meg) except I cannot get the ram image to load from HD3. I've tried just
I am presently having the same trouble. I'm trying to run Minix
on a Zenith 386. One thing I have discovered is that you can Boot off
of the Universal Boot Disk and everything will work... Till you recompile
the kernel for an AT. Then the problem reoccurs. {Also using the
Universal Boot disk will read the system clock, For some reason the AT
Boot disk makes you enter the day and time etc. at least on my system}
Are you getting something like this after it says to 'insert /usr
disk in fd0' or something to that effect?
Nonmaskable interrupt
process number -4, pc = 0x0005:0x00005625
Kernel panic: exception in Kernel, mm or fs
Type any key to reboot
If you figure out how to fix this problem, please {PLEASE} let me
know what to do.
Thanks,
Robert Douglas
douglas@geo2s.mps.ohio-state.edu
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From: IN%"cs551beb@iitmax.iit.EDU" "Bill Edward Bach" 7-MAR-1991
Subj: RE: Problems with using /dev/hd3 as ram image
From: Bill Edward Bach <cs551beb@iitmax.iit.EDU>
Subject: RE: Problems with using /dev/hd3 as ram image
Newsgroups: comp.os.minix
Organization: Illinois Institute of Technology
For your problems with the RAM disk, this is a problem which one of the
members of my class has had similar problems with. If you don't get this
solved in the next few days, reply to me and I will try to find him to see
if he has a solution yet.
So far, he is using hd3 as the root device, with no RAM disk. I will give him
your netname, but I don't know how adept at E-mail he might be.
Good Luck! Bill Bach: BACHBIL@karl.iit.edu
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From: IN%"paula@atc.boeing.COM" 7-MAR-1991 14:56:59.81
Subj: RE: Problems with using /dev/hd3 as ram image
From: paula@atc.boeing.COM
Newsgroups: comp.os.minix
Organization: Boeing Computer Services Advanced Technology Center
In article <1991Mar6.145656.53@cudnvr.denver.colorado.edu> you write:
>I recently bought Minix 1.5 from Waldensoft. Everything seems to work fine
A couple things come to mind. First, Minix tries to load a ramdisk of
512K or greater in extended memory above the 1Mb mark. Second, you only
have 640K of useable memory, and don't have enough for a ramdisk even
as big as 360K. There has to be some space for the kernel and some
processes. If you dd the 1.5 ramdisk image floppy onto /dev/hd3, can
you get the ramdisk to load from /dev/hd3? If that doesn't work, but
loading it from the original floppy does, then something's wrong.
If I were you, I'd skip the ramdisk and just put the root on /dev/hd3.
With the root on a ramdisk, you always have to be careful not to shut
down the system without copying changed files (like /etc/rc or
/etc/passwd) to disk. You'll probably want the memory for processes at
some point, and the ramdisk doesn't speed things up that much. I've
got 4Mb on my Minix machine and used to run with a 300Kb ramdisk
mounted on /tmp. When I tried to compile the GNU C compiler, I had to
give up the ramdisk and hand-optimize the stack size of each compiler
pass to get everything to fit. I didn't notice the speed difference
with /tmp on the hard disk and haven't bothered to switch it back.
Paul Allen
--
------------------------------------------------------------------------
Paul L. Allen | pallen@atc.boeing.com
Boeing Advanced Technology Center | ...!uw-beaver!bcsaic!pallen
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From: IN%"wolff@duteca.et.tudelft.nl" 12-MAR-1991 08:54:28.93
Subj: RE: Problems with using /dev/hd3 as ram image
From: wolff@duteca.et.tudelft.nl (Rogier Wolff)
Subject: RE: Problems with using /dev/hd3 as ram image
Newsgroups: comp.os.minix
Hi,
1 meg of memory in PC's is configured as a contiguous block of 640K.
The remaining 384K is usually mapped to the region just above 1M.
This means that you can get a 360K ram disk into that region. However
the other possibility that some manufacturers do with that "excess"
memory is to make it "Epanded" memory: bank switched at some address
between 640K and 1M. Minix cannot use that memory. Have a look at
what minix mentions about the available memory at boot time.
200 (minix) + 512(ramdisk) > 640 : doesn't fit into main memory.
By the way, I run out of memory really easy, I don't use a ramdisk,
just to save valuable memory.
(hope these ramblings help,)
Roger