Hi, thanks a lot for your help, I do appreciate it 😊
I'll try to answer your questions, I am not that skilled on linux.

About version, see the output:

[rafael@fermi ~]$ cat /etc/*release

NAME="Scientific Linux"

VERSION="7.4 (Nitrogen)"

ID="rhel"

ID_LIKE="scientific centos fedora"

VERSION_ID="7.4"

PRETTY_NAME="Scientific Linux 7.4 (Nitrogen)"

ANSI_COLOR="0;31"

CPE_NAME="cpe:/o:scientificlinux:scientificlinux:7.4:GA"

HOME_URL="http://www.scientificlinux.org//"

BUG_REPORT_URL="mailto:[log in to unmask]"


REDHAT_BUGZILLA_PRODUCT="Scientific Linux 7"

REDHAT_BUGZILLA_PRODUCT_VERSION=7.4

REDHAT_SUPPORT_PRODUCT="Scientific Linux"

REDHAT_SUPPORT_PRODUCT_VERSION="7.4"

Scientific Linux release 7.4 (Nitrogen)

Scientific Linux release 7.4 (Nitrogen)

Scientific Linux release 7.4 (Nitrogen)


Well, I didn't know anything about epel or dkms. When trying to install Nvidiz by Yum, there were dependencies. then I look for dkms. The Dell site recommended to install epel in advance. Thus there were a chain of packs I supposedly had to install in advance. 

So I did $yum install epel, next I've downloaded the dkms rpm and installed via yum as well. Next I've installed Nvidia drivers by $yum install *nvidia*

Then I've accessed a Nvidia visual app installed but did nothing there. I've assumed the board was not visible yet by the system and then I've decided to reboot and try to load the drivers. What happens next you already know, the boot has freezed and I've tried to boot over again and again ever since.

Although freeze in the middle, when I hit <ctrl> <alt> F2 I can go to a shell and log in. Then I can do a lot, including run Gromacs or access this PC from my mac through ssh.

Once I can log in in the shell can I fix the system from there?

You've said I could recover the system booting from USB but I don't know how to do it. Should I have the Scientific Linux in a stick?

Thanks, Rafael


Rafael Guimaraes Pereira
[log in to unmask]
skype: wirttipereira
Celular:   (11) 9.6578.1661
Residencial:  (11) 2129 6957
https://br.linkedin.com/in/rafaelguimaraespereira

De: Nico Kadel-Garcia <[log in to unmask]>
Enviado: domingo, 28 de janeiro de 2018 17:06
Para: Wirtti Pereira
Cc: [log in to unmask]
Assunto: Re: Boot hang after [ OK ] Mounted Arbitrary Executable File Formats File System
 
On Sun, Jan 28, 2018 at 5:28 AM, Wirtti Pereira
<[log in to unmask]> wrote:
> Hi, I've been using SL for a couple of months. I'm setting up a PC to run
> Gromacs 5.1.4. It was running rime with CPU. Then i've installed a NVidia
> 2070M and start trying to compile. It happens to have several dependencies
> and I was installing one after another.
> The last packages I've install before the boot problem were EPEL and DKMS.
> After have these packs installed I've rebooted the machine once to have the
> drivers loaded (unfortunately I don't know how to do it on the fly). Then
> the I've couldn't make it boot again. I've tried safety mode boot also. I've
> removed the NVidia card but it keeps freezing.
> What else could I do?
> Thanks in advance, Rafael

That does not sound like a Scientific Linux issue, per se. That sounds
like "I tried to compile in new kernel modules when I added my NVidia
card, and stuff got broken" issue. We might be able to help.

Which version of Scientific Linux do you have installed? I don't see a
"dkms" package for SL 6, I assume you installed the dkms" package from
EPEL for SL 7.

Can you boot with Scientific Linux installation media, such as a CD or
USB frob, using the livedvd or installation DVD image in rescue mode,
so that you can get at the filesystem of your original OS ? In
production enviironments, I personally like to set up a PXE setup so
that I can boot to rescue media just using the local network
connections, but I suspect that is more work than you need right now.
Booting with such media should also make your network available, and
let you copy critical personal work elsewhere. This is why I like USB
frobs for doing that kind of rescue boot: it lets me copy files from
the system being rescued to the rescue media itself, so I don't have
to do more.

Let's look at what you've done recently. Activated EPEL, meaning did
"yum install epel-release", and made EPEL rpm's available? Right,
should not have touched kernel or base OS because EPEL is really
careful to avoid overwriting the base RHEL published or Scientific
Linux republished packages. Installed dkms from EPEL? Right, that
should have enabled the building of dynamically loadable kernel
modules. Installed a powerful NVidia card, presumably to use the GPU?
Right. I suspect you grabbed NVidia kernel code from somewhere and
tried to hand-install NVidia modules, and lost the ability to reboot?

"Start trying to compile."  NVidia tools, on top of a previously
working kernel you could boot with? Or Gromacs, and that maybe
detected your NVidia card and started trying to install modules?