When my bad memory worked out for the best

TL;DR: Blue screen of death is commonly caused by bad memory! Bad memory can manifest itself in lots of different ways, and is different between operating systems. I saw BSOD in Windows, and kernel panics only when copying large files in Ubuntu. Bad Memory prompted my move to Ubuntu as my main operating system, but it wasn't without woes!

~

About a week ago, my MSI GT70-2OC running Windows 10 started acting weirdly. I leave the laptop on 99% of the time running Universal Media Server to allow me to watch the media I have stored on it anywhere in my home. Usually on my smartphone whilst washing up, or on my living room TV using my PS4.

I first noticed that now and again UMS would be in-contactable. Physically checking my laptop I'd see that it was at the login screen. After being certain I wasn't going mad and rebooting or forgetting to login, I checked the event logs to find that quite regularly, the laptop was rebooting due to a bugcheck (more commonly known as the Blue Screen of Death!).

Checking the logs further I could see that Microsoft had released an October Driver Pack around the time that I started having problems. I'd had driver issues frequently since upgrading from Windows 8.1 to 10, as MSI no longer support my model, they haven't released official Windows 10 drivers. Unfortunately, Microsoft also auto-install driver updates. There are ways of stopping them from being installed, but this is on a per-update basis, so unless you are eagle-eyed there is a good chance you won't notice until the driver goes on, and in my case, the track pad stops working!

Presuming it was a driver issue, and because I had some time on my hands, I decided to bite the bullet and browse for the most user-friendly version of Linux available. I pulled out my 10 year old laptop (still going strong, also an MSI!) and began browsing the Internet. By this point, my GT70 was unusable, rebooting with a BSOD after every login attempt. After some browsing, I came across Ubuntu 16.04 LTS. Supposedly user-friendly, and the screenshots looked beautiful. I downloaded the ISO image, burned to disk and attempted the install. It failed on three separate attempts. So I grabbed the checksum, and compared the two and noticed the checksum of the ISO I burned to CD was different. This usually means that the ISO become corrupt during download, or when burning to the CD (moral of the story; time and effort can be saved by checking the checksum!).

So I went back to the Ubuntu download site, grabbed the ISO again and compared the checksum. It showed up OK, so presumably the disk burner on my 10 year old laptop is giving up the ghost a little and caused the issue. So, let's get with the times (who uses CDs anymore?) and go for the USB boot method. The process was surprisingly simple from this page, and it not only allows you to install Ubuntu, but also acts as a bootable version, which can be very useful if you lose access to your OS for whatever reason.

So, I booted from the USB and ran the install successfully. I chose to format my 2x RAIDED 128GB SSD's and install Ubuntu here, as I didn't want to lose my media on my 750GB mechanical. The process was a lot quicker from the USB, and I was soon booted into a beautiful Ubuntu desktop.

Now I started to hit some more issues, and it was already getting to 11pm. Firstly, the disk containing my media couldn't be mounted. An error message appeared to say that it contained hibernation data on it, and therefore could only be opened in read only mode. I did some digging and Windows 10 uses a feature called "Fast Startup", that essentially always keeps the OS in hibernation to give you quicker boot times. The workaround, of course, was to boot back into Windows, remove the hibernation file and disable Fast Startup. Impossible for me as I had gone the whole hog and nuked my Window setup!

I could mount the disk in read-only mode using the following command so at least I could still get to the data.

mount -t ntfs-3g -o ro /dev/sda3 /media/windows


So the best course of action would be to backup the data, wipe and re-partition the disk (this would also allow me to use the Linux friendly ext4 file system over Windows traditional NTFS). So I began copying off of my 600GB of media onto a USB hard disk I had lying around. Then I hit my next problem...

After around 5GB of transfer, my laptop would freeze completely, with just the Num Lock LED flashing. I had to hard power down the laptop and log back in but every time I tried to copy the files, to either the USB hard disk or my RAIDED SSD, I hit the same issue.

Alas, I called it a night there, to tackle another day. I had a working laptop, running a nice new OS, UMS was working so the wife and I could carry on watching Arrow and The Flash, and we had our boy's favourite "In the Night Garden" ready for when he wanted it. Only downsides were that I couldn't write to my 750GB disk, and I hadn't even begun to ponder whether my Nvidia Graphics Card was working to its full potential. Or so I thought...

So the next day, I did some research into the flashing Num Lock and freeze when copying files, and the most common answer tended to be dodgy RAM. At this point something clicked. When I had seen Blue screens in the past on Windows, it was almost always down to a dodgy RAM stick. Could it be that one of my RAM sticks were faulty, and it was actually this that was causing my problems all along?

Only one way to find out. I jumped onto my old laptop, went to http://www.memtest86.com/download.htm, and downloaded the bootable USB image. I followed the instructions at http://www.memtest86.com/technical.htm#win to create the USB stick and soon had booted my GT70 into memtest. I kept the default settings and started the test, and quickly the errors were in their thousands.

So I'm fairly certain I've got some bad RAM. Next, I wanted to find out which RAM stick was causing the issues. I have two 8GB sticks that came pre-installed. I wanted to run memtest with only one of the sticks installed to see if the errors dissappear. I found https://www.youtube.com/watch?v=QkL5q1-K15s and got to work taking my keyboard off and getting to my RAM. I quickly found the suspect RAM stick, took it out and began transferring my media off again. It worked perfectly!

Meanwhile, I headed over to uk.crucial.com and got myself a new 8GB stick of RAM. Once the transfer was finished, I used Gparted to wipe and repartition my 750GB using the ext4 file system. Copied everything back and the laptop was working perfectly.

There was one last thing for me to do - get my hybrid graphics working. But that deserves its own separate blog post.

So it was a torrid time, but I'm extremely happy with Ubuntu 16.04 LTS. Its a beautiful, slick and responsive operating system. It actually feels like its unlocked some hidden potential in my GT70, which is nearing 4 years old now.