On Mon, Jul 26, 2021 at 01:02:17PM +0100, Bev Nicolson wrote:

I think I shall have to boot from a live disk soon to work this one out. The whole thing freezes sometimes (just now for example) and absolutely nothing - no key stroke, nothing - does anything. Except pressing the power button. Not ideal.

That sounds annoying, you might want to give memtest86 a go on your hardware and check that all the fans in your computer are spinning and it's not got any vents blocked with dust, especially in warmer weather it could be a hardware fault.

Adam

On Mon, Jul 26, 2021 at 06:58:00PM +0100, Bev Nicolson wrote:

I've got memtest86 on a usb stick now. How do I use it? What's a cycle for example, in this case?

I should have been more clear, you actually (most likely) want memtest86+ from https://www.memtest.org/ for how to use it's fairly straight forward but the easiest way would be to watch a video on youtube or similar which will explain it more visually than I will be able to do over an email.

Adam

On 30/07/2021 15:54, Bev Nicolson wrote:

I've done that (5 passes not 10, mind, but it took nearly 5 hours) and no errors, curiously.

How do I proceed with the live disk? What would I be looking out for to report back on?

If it was me, I'd try booting from the live disk and

1) checking all the hard disk partitions on the machine (except any partition that's formatted for swap, as there's not a fsck for that).

It's perhaps easier to launch the test from gdisks (Disks) or gparted if either is installed.  Alternatively, you'll have to work out what your partition names are and do a manual fsck on each of them.

e.g.

sudo fdisk -l

snip Device         Size Type /dev/sda1     [snip] BIOS boot /dev/sda2     [snip] Linux filesystem /dev/sda3     [snip] Linux swap

I'm not aware of how to fsck a bios_grub partition, or a swap one, so I'd have to check /dev/sda2

read up on fsck to get the right flags.

If you have more than one hard disk, check them all. If you have a RAID array, or you are using LVM (Logical Volume Manager), do more research first otherwise you could break things by using FSCK.

2)  Does your system work if you run it for a while from the live disk?  If it does work, it's likely to be some software on your installation that's gone wrong.  If it does not work, it's likely to be a hardware error.

Not using the live disk, you can check the time when your computer crashes, then examine the log files and see if anything happened at that time.  Personally I like the command line app lnav (sudo apt-get install lnav).

you can use lnav to look at several log files simultaneously.  e.g.

cd /var/log sudo lnav auth.log auth.* dmesg dmesg.*

then you can scroll up and down to the time the machine crashed and look for errors.

Good luck

Steve