Errors when copying files?

[Bartman]

If I copy a file, and the copied file is different from the original, are there any other possible causes besides a faulty hard drive?
I tried copying a 128MB file 15 times, and only 11 times the resulting md5sum was the same as the original.

My hard drive uses reiserfs with a 2.4.20 kernel.

[pbharris]

hello,
faulty memory may also cause this.

[Bartman]

I found a program called memtest86 on freshmeat, I ran it and it didn't give any errors. So I assume it really is my hard drive. Is there a way to fix this, or at least work around it?

I know that you can check your hard drive for bad blocks with e2fsck, but I haven't found such a program for reiserfs.

[coltrane]

its exists....brb with that info

*coltrane consults his linux bible*

[coltrane]

reiserfsck

[cloverm]

fsck.reiserfs is what you're looking for usually found in /sbin.

[Bartman]

Thanks for the reply, but that's not actually what I am looking for. reiserfsck only checks for a good filesystem structure (it found no errors), it doesn't check for a faulty hard drive. It could very well be that it is even impossible to do that with reiser, that reiserfs just assumes that your storage is ok. With ext2 you can check for bad blocks.

I have been considering to reformat with ext2fs just for that reason.

[demian]

The program to scan your hdd for bad blocks is called .... drumroll badblocks. And it works no matter what filesystem you use.

The fact that memtest86 didn't say your RAM is borked is nice and all but doesn't say much. Such a program might be able to tell you something's wrong with your RAM but it cannot reliably tell you that everythings right. A device to test that would cost you a few kilobucks...

[Schotty]

My experience has shown that memtest works VERY well at finding problems with RAM. Run it for at least 12 hours (prime run time is 72 hours IMHO), and you will see problems if you have any. But the best option, is yes a hardware tester .. and those are not cheap. Several thou easily. The one at the local U cost around 4K. Handles all current ram types (SIMM, DRAM, RDRAM, SDRAM, DDR, parity bit modes for each).

Seriously -- have you tried another physical disk? Or wiping the disk and starting fresh (low level format ... the whole nine yards) ?

[Bartman]

[quote author=demian link=board=3;threadid=6989;start=0#65201 date=1052938361]
The fact that memtest86 didn't say your RAM is borked is nice and all but doesn't say much. Such a program might be able to tell you something's wrong with your RAM but it cannot reliably tell you that everythings right. A device to test that would cost you a few kilobucks...
[/quote]

I ran memtest86 last night for 11 hours. I assume that a program designed to check for RAM errors should find errors if there are. You don't expect to have a simple `cp` fail because of bad memory, when memtest cannot find any errors.

badblocks did give errors, but it seems reiserfs can't handle that, so I will reformat everything with ext3, unless anyone here has a better idea? reiserfs might have better performance, but I'd rather have something which works.

Oh, and if a professional mem tester costs that much, I might as well buy 2 or 3 brand new computers for that price