Questions[memtest](ubuntu)

Hey there I am doing yet another edit with newly gathered information. So far there has been few responses here, so this will probably be the last one.

I am running a ThinkPad P14s with Ubuntu 20.04. Some times the machine freezes completely and I have to hard reset it.

I am almost sure this does not happen because I am running out of RAM or the machine getting to hot.

Of course I want to track the root of the problem, but I also want to learn more about how to approach these problems in general as I have little knowledge of Ubuntu and Linux in general. So what log file and setting should I look at? What am I looking for? Maybe there are also guides that you could link me to. Although I get overwhelmed by those quite fast. A similar question has been asked here (Tracking down a random freeze?) and /var/log/syslog is mentioned there but the question of what to look for was not answered.

I have gathered some additional information that hopefully can enable some one to help me.

Occurrences and graphics card

I am not 100% certain but I think the freezes occur exclusively when

• watching a DvD / Blueray
• streaming videos
• during games

I changed what graphics card is used with prime-select [nvidia | intel]. But the freezes occur in both setups.

no REISUB

When a freeze occurs I cannot reboot the system with SysRq + R E I S U B. From what I understand that is not the case for "most" system crashes. Does that lead towards some possible problems more that towards others?

memtest

I tried to to do the steps here but holding Shift did not open GRUB. After some searching I found that I can change /etc/default/grub such that I have:

GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10

Now GRUB opens on every reboot, but there is no option memtest86+ available. I checked that /etc/grub.d/ contains the executable file 20_memtest86+ and I also checked all options under "advanced" in GRUB.

What else could I try in order to run memtest?

psensor

I do not think my problem comes from overheating. The last couple of freezes happened when my Laptop felt relatively cool. I use "psensor" to constantly track the temperature.

problems on reboot

This may or may not be related. I recently was trying to load a save game of some game but the game crashed every time. I decided to reboot the system to see if that helps but the reboot could not be completed! Instead the following was printed:

Virtual device wlp0s20f3 asks to queue paket!
sytemmd-shutdown[1]: Could not detach Dm /dev/dm-0: Device or resource busy
sytemmd-shutdown[1]: Failed to finalize DM devices, ignoring
sof-audio-pci 0000:00:1f.3: error: no reply expected, received 0x0
xhci_hcd 0000:2b:00.0: Host halt failed, -19

I had to hard reset after this. What does that mean?

My computer is very old, and uses DDR2, with a max of 8 Gigs of RAM. I recently replaced the two RAM cartridges in my computer with enough RAM to max it out. But, just a while ago, I tried to run a Memtest, and it froze before it even finished 1% of the first pass. The RAM has been functioning fine on the regular computer, and is detected by the Memtest, but it just won't progress, and I have to turn it off and on again to exit the Memtest (esc doesn't work). Does anybody know what's going on?

I am running Ubuntu from flash drive and I would like to run memtest in terminal mode as multiple processes, I see file resides in boot directory but not able to execute as I get message "permission denied" not able to make the file executable either.

I'm having problems with my old laptop: Ahtec clevo m7xsun from 2009, xubuntu 16.04 64 bits, kernel 4.4.0.25 and upstream 4.7.0.22 for testing. There are 4 GiB of installed RAM in 2 modules. Sometimes the BIOS detects the whole 4 GiB, sometimes just 2. I have exchanged the modules several times, so I don't believe one of the modules is broken. I was suggested to run memtest, which I did, and as you can see in the picture, after having finished a first pass in almost 2 hours, it didn't detect any errors.

I marked 3 points in the picture: 1, 2 and 3:

1: 2048M - 3070M 1022M of 4093M: the only thing I understand is 4093M (4 GiB RAM, my total ammount of RAM. What do the other numbers indicate?

2: Please notice this is a dual core laptop (2 DUO CPU), this has to do with question 3.

3: If my laptop is a dual core one, why does memtest show: cores: 1 Active / 1 Total (Run: All)? shouldn't it indicate 2 total? and if it is running All, well, memtest is only detecting one core out of two, and something is wrong with my laptop.

If using UEFI Please see this question, "Can I boot memtest86+ if I'm using UEFI?"

After having installed the 64bit version of Ubuntu 12.04 on my Lenovo B570 I ran into the same problems I had when installing 11.10 with Grub not playing nicely with a uEFI system. I used the same technique as last time to solve the problem (using a Super Grub Disc LiveCD session to repair Grub) and my system happily dual boots between Ubuntu and Windows 7

However now when I boot up the Grub menu only displays

• Ubuntu, with Linux 3.2.0-24-generic
• Ubuntu, with Linux 3.2.0-24-generic (recovery mode)
• Previous Linux versions
• Windows 7 (loader) (on /dev/sda1)
• Windows Recovery Environment (loader) (on /dev/sda4)

I no longer see the option to use Memtest86+ which was there previously, having checked in the Ubuntu Software Center I can see that the package is installed, but how to I make the option to run it once again appear in the Grub menu?

I've tried:

sudo update-grub 

which doesn't make any difference.

sudo chmod +x /etc/grub.d/20_memtest86+ 

results in:

chmod: cannot access /etc/grub.d/20_memtest86+': No such file or directory

and entering

ls /etc/grub.d/

results in:

00_header        10_linux      30_os-prober  41_custom
05_debian_theme  20_linux_xen  40_custom     README