Uncompression error - System halted

[Fernando]

Hi everybody.
This morning my computer, running 18.04, froze when watching a video. It froze to the point of having to hard-reboot. When rebooting, a message of "uncompression error - system halted" appeared. I tried a couple of times with the same result (even with older kernels) and finally resolved to run MemTest86 to see if there was some problem. Well, it found some 32000 errors in almost 2 hours of checking my 4Gb of RAM (two DDR3-2Gb-modules). Since it was the first time for me running these tests and didn't know quite much what to make of them, after the 120 minutes I got tired and choose to exit and reboot again. To my surprise, the system initiated normally with no errors and it seems to be working OK by now, almost four hours later.
My questions are:
1- Is the "uncompression error" usually related to RAM problems or can it be also related to HDD issues or some other thing?
2-Should I worry about those 32000 errors detected by MemTest86 or can they be somehow temporary? Maybe I should start thinking of getting new RAM modules?
Thanks in advance!

[GreyGeek]

That error can have several causes: not enough RAM for the system or process you are running, turning on hard drive compression, pending HD failure mode, bad NIC ....
In those cases the problem was resolved by: switching to a distro with a smaller footprint, turning off HD compression, replacing the HD, getting a new NIC ...l

[Fernando]

Wow, that was fast! Thanks GreyGeek!
Now...
1- How can I see if I have HD compression turned on, and how to turn it off if necessary?
2-What do you mean by a smaller footprint? Less use of resources/more efficient use of them? Any recommendations?
3-What is a NIC??
Again, many thanks!

[GreyGeek]

1. IF you didn't turn it on then either it came already turned on, or some app turned it on, or it is not turned on. Personally, I never use HD compression and don't keep current on it.
2. Run a smaller distro, like PuppyLinux, etc... One that uses less RAM that Ubuntu or Kubuntu or Mint, or SUSE ....
3. NIC Network Interface Card. Sometimes, with no cable plugged into Eth0 your computer can boot fine, but plug in a cable and it hangs ... usually because the NIC has become defective.

Perhaps the video buffer became full. Do you have a swap file or partition? If so, how much of it was used? All of it? If you don't have a swap file then perhaps creating a swap file (IF you are not using Btrfs) will give you some extra "RAM". OR, upgrade your RAM to 8GB?

[oshunluvr]

"uncompression error - system halted" when booting means not enough RAM to uncompress the initramfs. Your RAM may be going bad or motherboard is. You might try removing the RAM and sticking it back in. Sometimes a bad "connection" will cause this.

[Rod J]

Re-seat your ram sticks and then run the memtest86 again for a while. If there are NO errors after running it through a complete pass it may just have been a bad connection as oshunluvr suggested.

On modern PC/laptops it's much less common to have bad connections with the memory, but I remember in the early days of my computing that I was always having to pull out the memory chips and re-seat them to fix problems.

[Fernando]

Thanks everybody.
The system is working now, but I'll try to remove and reconnect the RAM chips and run MemTest before deciding to buy new chips.