tool for check memory

[idima]

Do you know any tool for verifying the integrity of the memory without shutting down linux?

[bigtomrodney]

I could be mistaken but I think you'd need direct hardware access to the RAM to check it. Most people stick to Memtest86 which does a great job, but you would have to shut down.

[idima]

Ok, then I will try something else. I'm going to restart the computer at night to boot by default with the memtest of grub.
But I have 2 questions:
- What does the memtest when it ends? Boot linux?
- How can I see results the next day?

[D-cat]

Memtest keeps running (just repeating tests) until it is manually inturrupted or configured to stop and do something else (like reboot) after it is started. Memtest doesn't have filesystem access, so you can't put the settings in a file for automatic configuration.

The other part of that is you can't write the results to a file. Therefore, it's probably best if it's still running when you get in in the morning. This way you can glance the status screen and see if there are any failed addresses (they show up in red).

[htismaqe]

Like D-cat said, memtest doesn't stop running until you stop it. Even if it encounters THOUSANDS of errors, it won't stop.

I used to be an avid overclocker and have quite a bit of experience with memtest. I have to ask, what are you wanting to use it for?

Unless you're having crashing issues, it's unlikely that your memory is the culprit, for one. And two, to really make sure your memory is stable, you need to let it run for a long time. Some people will say 8 hours is enough, but I've also seen recommendations of at least 72 hours. I've had it find errors in overclocked memory after 24 hours, so it's really not something you just run for a few minutes and go.

[idima]

Ok, i understand.
I want to check memory because I got a bug when I did a backup and the bug said it could be memory or other hardware.
Today, I found a tool called MEMTESTER, which can run without shutdown. I will try this tool, if it not find errors then i let the memtest running at night.

[htismaqe]

Ok, i understand.
I want to check memory because I got a bug when I did a backup and the bug said it could be memory or other hardware.
Today, I found a tool called MEMTESTER, which can run without shutdown. I will try this tool, if it not find errors then i let the memtest running at night.

I've never used Memtester, but I wouldn't trust any memory checking app that runs from within an OS. You need to be running it as a bootable so that you're checking the memory directly and results aren't being muddled by your OS' memory access.

And what kind of a bug did you have? Memory errors will almost ALWAYS cause complete OS failures - ie. BSOD in Windows. Chances are an error in your backup program is disk-related.

[D-cat]

Memory errors will almost ALWAYS cause complete OS failures - ie. BSOD in Windows

Not necessarily. RAM that lacks ECC controls and goes bad further up beyond the kernel space can sit there and reek all sorts of havoc before you figure out what's really going on... everything from inconsistent UI behavior, random inexplicable program faults, to corrupted files (buffered through the bad RAM on their way to saving). By the time you do finally get a consistent panic or BSOD, damage has been done to the data and there's a limit to how much you can accurately recover.

Either way though, you can only reliably test memory that's not currently in use, which is why a clean boot with Memtest86 is far better than any aftermarket memory tester running on top of the OS.

[htismaqe]

Not necessarily. RAM that lacks ECC controls and goes bad further up beyond the kernel space can sit there and reek all sorts of havoc before you figure out what's really going on... everything from inconsistent UI behavior, random inexplicable program faults, to corrupted files (buffered through the bad RAM on their way to saving). By the time you do finally get a consistent panic or BSOD, damage has been done to the data and there's a limit to how much you can accurately recover.

Either way though, you can only reliably test memory that's not currently in use, which is why a clean boot with Memtest86 is far better than any aftermarket memory tester running on top of the OS.

That's why I said "almost" always. While non-ECC memory can have errors that have those types of effects, it's extremely uncommon, at least in my experience.

That being said, IF those are the kind of errors we're talking about, memtest will ABSOLUTELY need longer than 8 hours to find them in all likelihood.

Also, because of the nature of his error, I would run an integrity check on the hard drives first.

[D-cat]

I've been bit by that scenario twice (well, a friend and a customer machine)... and memtest86 found a bunch of the bad addresses in about 30 seconds.