# [SOLVED]Emerged memtest86 reports error other versions don't

## deadearth

I hope this is the right forum for this, but here goes:

Bought a new small form factor pc: http://www.newegg.com/Product/Product.aspx?Item=N82E16856176002

Worked great for about two weeks until XBMC and glxinfo started segfaulting out of nowhere.  Suspecting a memory error, I emerged and ran memtest86.  Within about 30 seconds it started throwing errors.  I tried two other sticks of ram and the same issue. 

Suspecting it was a product defect of the computer I filed an RMA and got a replacement.  It comes and I replace it with the hard drive from the first machine and I still get the same issue.  Glxinfo segfaults and memtest86 throws errors within about 30 seconds.  

Now i turned my attention to the hard drive and installed gentoo on a new hard drive from scratch only emerging grub and memtest86 (enough to get memtest86 bootable).  Booting to this drive also reported memory errors.  

Booting from a usb stick with the gentoo live image applied results in no errors.  I even copied over the memtest86+ bin file from a fedora install (from their memtest86+ package) into my gentoo disk to see if booting from the disk had something to do with it, but it resulted in no errors as well.

Why is a memtest86 throwing errors when emerged from Gentoo ?     I think I've done all I can to eliminate hardware as the cause.  I haven't tried re-emerging the full system to test the xbmc/glxinfo segfault, but I'm not sure there is a reason until i can figure out this memtest86 issue.

Thanks!Last edited by deadearth on Tue Aug 02, 2011 2:44 pm; edited 1 time in total

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## NeddySeagoon

deadearth,

You cannot usefully run memtest86 while the kernel is running.

The kernel gives each process its own memory map and can and does move things around with the process being entirely unaware of this.

This makes memtest86 report errors.

memtest86 must run on the bare hardware - without linux. Its a boot option the liveCD. Run it from there.

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## deadearth

Sorry, i probably should have been more clear.  Every instance I 'run memtest86' in the original post, i'm booting from GRUB.   I know that you can't run memtest86 by itself.  I emerge memtest86 and added a grub entry for it (per the emerge instructions).  

Memtest86 is booting just fine in all cases (from grub on the hard drive, usb stick etc..), its just when i boot from grub using the binary that was emerged within gentoo it gives memory errors very quickly.

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## John R. Graham

Yes, and memtest86+, which is also in Portage, does not. I've recently noticed this issue with memtest86, too. Just haven't experimented with it enough yet to understand what the issue is.

- John

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## deadearth

Oh!!!   I did not realize that there was a difference between memtest86 & memtest86+ !!!!  I will have to test out memtest86+ when i get home, but I bet that is the issue.

Thanks John!

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## deadearth

Turns out my original issue was: https://bugs.gentoo.org/show_bug.cgi?id=350336

silly binary driver :{

I was just on a wild goose chase with the memtest issue.  All is well!

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