# My gentoo has becomed very weird :S CRC errors and full ram

## Terrax

Hey gentoo

My gentoo has become weird for the last month. I haven't done anything about it, because it runs okay. But there is some minor issues.

1. My Fysical memory "ram" is becomming fully used very fast. After about 20 min, the ram is fully used (Also when I do not run anything, other than kde)! Though my swap isnt used at all?

2. When I burn or unpacking any bz2, zip, rar or whatever, 60 % of the time, it reports a CRC error. But when I try again right after, its another file, which has the CRC error. I have checked my memory in memtest86 once. And it didn't report any failure. My harddisks is quite new. And by the way. It doesnt matter, if I unpack a compressed file from my old disk or the new (same errors).

My ram modules is 2x512 mb dual channel GEIL.

I really hope there is a solution. Can it be my kernel-way to use my memory? I have a amd64 by the way.

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## frenkel

1) Search for full ram, there are hundreds of post about it. Linux likes to cache things in ram, there is nothing wrong with it, as ram is faster then harddisk. As long as it is not needed for anything it will cache stuff in memory.

Empty memory == useless memory.

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## Terrax

#2 ok thx. New knowlegde doesnt hurt  :Smile: 

But what about the failures? Can it has something about i disabled IOMMU in the kernel? (amd64 memory controller I think).

I have to disable that, so I am able to disable agpgart. (I use nvagp).

But as far as I know you only have to have IOMMU enabled if you have over 4 gb memory?

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## frenkel

I don't know, it might also be something with your CFLAGS (too much optimization cause weird behavior). Can you post your CFLAGS?

If I were you I would run memtest86 again and let it run for a few hours.

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## Terrax

```

     emerge --info

Portage 2.0.53 (default-linux/amd64/2005.1, gcc-3.4.4, glibc-2.3.5-r2, 2.6.14-gentoo-r5 x86_64)

=================================================================

System uname: 2.6.14-gentoo-r5 x86_64 AMD Athlon(tm) 64 Processor 3200+

Gentoo Base System version 1.6.14

dev-lang/python:     2.3.5-r2, 2.4.2

sys-apps/sandbox:    1.2.12

sys-devel/autoconf:  2.13, 2.59-r6

sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1

sys-devel/binutils:  2.16.1

sys-devel/libtool:   1.5.22

virtual/os-headers:  2.6.11-r2

ACCEPT_KEYWORDS="amd64"

AUTOCLEAN="yes"

CBUILD="x86_64-pc-linux-gnu"

CFLAGS="-O3 -march=athlon64 -pipe"

CHOST="x86_64-pc-linux-gnu"

CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.4/env /usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/kde/3/share/config /usr/lib/X11/xkb /usr/lib64/mozilla/defaults/pref /usr/share/config /var/qmail/control"

CONFIG_PROTECT_MASK="/etc/gconf /etc/splash /etc/terminfo /etc/env.d"

CXXFLAGS="-O3 -march=athlon64 -pipe"

DISTDIR="/usr/portage/distfiles"

FEATURES="autoconfig distlocks sandbox sfperms strict"

GENTOO_MIRRORS="http://mirror.uni-c.dk/pub/gentoo/"

LINGUAS="da"

MAKEOPTS="-j2"

PKGDIR="/usr/portage/packages"

PORTAGE_TMPDIR="/var/tmp"

PORTDIR="/usr/portage"

PORTDIR_OVERLAY="/usr/local/zugaina-portage"

SYNC="rsync://rsync.europe.gentoo.org/gentoo-portage"

USE="amd64 X alsa arts audiofile avi berkdb bitmap-fonts bzip2 cdr crypt cups curl dvd eds emboss encode esd ethereal exif expat fam ffmpeg foomaticdb fortran gif glut gmp gnome gnutls gpm gstreamer gtk gtk2 idn imagemagick imlib ipv6 java jpeg kde kdeenablefinal lcms ldap lzw lzw-tiff mad mng motif mozilla mp3 mpeg ncurses nls nsplugin ogg openal opengl oss pam pcre pdflib perl png ppds python qt quicktime readline samba sdl spell ssl svg tcpd tiff truetype truetype-fonts type1-fonts udev usb userlocales vorbis xine xml2 xmms xpm xv zlib linguas_da userland_GNU kernel_linux elibc_glibc"

Unset:  ASFLAGS, CTARGET, LANG, LC_ALL, LDFLAGS

```

Ill run a memtest86 tonight. But anything else it could be? It didn't do so when I for two month ago installed gentoo.

Can it be my change from ext3 to reiserfs?

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## frenkel

No, the filesystem doesn't matter, because then the failures wouldn't be so random. If you try to unrar and it failes on file 1 sometime and on file 10 sometime, there is something else wrong.

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## Terrax

ok.

I did run memtest86+ for two hours now. No failure at all.

Can it be something with azureus, which I use to download legal thing with?  :Rolling Eyes: 

Or is it a unstable ark / bzip2 / tar program?

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## frenkel

How much memory do you have? You should run the advanced test, and that takes a lot more then 2 hour, especially if you have much memory. It can't be an issue with azureus, as they have hash checks. You have it with every archive you untar/zip/rar? Or just from one thing you just downloaded? The archive might be damaged when they uploaded it...

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## Terrax

frenkel

Yes I know the thing with azureus. I check it many times, before even try uncompress the arkives. By the way. There seems to be different, when I use different decomress programs. Tar doesn't make the failures as often as bzip2 does. And ark is useless, with some arkives.

By the way. I found a solution with the burnin problem I think. I just have to burn with 16x speed with my nec 3500a. No failure, at least yet.

I have 1 gb memory, the standard test is completed less in a halv an hour. Ill let it run the advanced test the whole night. Ill come up with the result tomorrow.

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## Terrax

Hmm actually Ill skip the memory test. Im almost sure it isn't the memory. By the way. I use memtest86+ not memtest86 (Its masked). And the memtest86+ doesnt include a advanced test.. MY memory have now passed 4 standard tests. Shouldn't that proff them clean?

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## frenkel

 *Terrax wrote:*   

> Hmm actually Ill skip the memory test. Im almost sure it isn't the memory. By the way. I use memtest86+ not memtest86 (Its masked). And the memtest86+ doesnt include a advanced test.. MY memory have now passed 4 standard tests. Shouldn't that proff them clean?

 

Advanced test will check every bit, standard won't test every bit..., but it's your choice, I can't help you anymore.

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## Terrax

Frenkel.

I don't see such a test in memtest86+. But I have testet my memory in 6 hours now, with 15 completed test without errors. 

What options do you use in memtest86 to test every bit?

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## frenkel

I didn't even know there were 2 versions of memtest, but it seems that this is default now (I used it 3 years ago).

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## Terrax

Ok  :Smile:  So what you are saying, is that I have used the advance test? 

Actually im running some decompress tests right now  :Smile:  Seeing if I can make som faults. Right now no one out of 2 were faulty (4gb archive).

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## Terrax

OK the third time, I tried to unpack the exactly same archive, I got this error message:

```

bzip2: Data integrity error when decompressing.

        Input file = (stdin), output file = (stdout)

It is possible that the compressed file(s) have become corrupted.

You can use the -tvv option to test integrity of such files.

You can use the `bzip2recover' program to attempt to recover

data from undamaged sections of corrupted files.

tar: Unexpected EOF in archive

tar: Unexpected EOF in archive

tar: Error is not recoverable: exiting now

```

I used this command to unpack a tar.bz2 archive:

```

tar -xjvf archive.tar.bz2

```

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## Terrax

Hmm I just remembered. For a month ago, I changes the position of my two 512 mb GEIL memory, so they was placed in dual mode. Before they were in single mode. Could that chance, have something to do with my problem now?

I get random crc errors when decompressing rar files too.

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## Terrax

When I run memtester 4.0.5. I get following errors by 35 % of the tests:

```

memtester 100

memtester version 4.0.5 (64-bit)

Copyright (C) 2005 Charles Cazabon.

Licensed under the GNU General Public License version 2 (only).

pagesize is 4096

pagesizemask is 0xfffffffffffff000

want 1000MB (1048576000 bytes)

got  1000MB (1048576000 bytes), trying mlock ...locked.

Loop 1:

  Stuck Address       : ok

  Random Value        : ok

  Compare XOR         : ok

  Compare SUB         : ok

  Compare MUL         : ok

  Compare DIV         : ok

  Compare OR          : ok

  Compare AND         : ok

  Sequential Increment: ok

  Solid Bits          : ok

  Block Sequential    : testing  68FAILURE: 0x4444444444444444 != 0x4444444444454444 at offset 0x0025d8b6.

  Checkerboard        : ok

  Bit Spread          : ok

  Bit Flip            : testing 115FAILURE: 0x00004000 != 0x00014000 at offset 0x0025d8b6.

  Walking Ones        : ok

  Walking Zeroes      : ok

```

Rest of the tests is succesfully? Is this my problem?

By the way... memtest86+ didn't detect any failure for 6 hours??? Thats 16 completed tests.

I run memtester in Linux, so could it be linux's way of handling the memory, which is wrong?

I have had thiese memorys for ages, and there haven't been any problem in windows.

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## Terrax

Some more tests:

```

memtester 500

memtester version 4.0.5 (64-bit)

Copyright (C) 2005 Charles Cazabon.

Licensed under the GNU General Public License version 2 (only).

pagesize is 4096

pagesizemask is 0xfffffffffffff000

want 500MB (524288000 bytes)

got  500MB (524288000 bytes), trying mlock ...locked.

Loop 1:

  Stuck Address       : ok

  Random Value        : ok

  Compare XOR         : ok

FAILURE: 0x90424b765dd8237b != 0x90424d765dd8237b at offset 0x0072976c.

  Compare SUB         : FAILURE: 0x5981860f3e4dc839 != 0x91573c0f3e4dc839 at offset 0x0072976c.

  Compare MUL         : FAILURE: 0x00000001 != 0x00000002 at offset 0x0072976c.

  Compare DIV         : FAILURE: 0xff33df2f2ff8cae1 != 0xff33df2f2ff8cae2 at offset 0x0072976c.

  Compare OR          : FAILURE: 0x99110e2104b00081 != 0x99110e2104b00082 at offset 0x0072976c.

  Compare AND         :   Sequential Increment: ok

  Solid Bits          : ok

```

The weird part, is that more failures, is in place, while I run in KDE?

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## numlock

Hi,

For me it seems you have a memory problem that is not detected by memtest86...

First, to be sure it's a hardware problem, I'd recommend you try booting with a LiveCD and run memtester from there..  so the testing would not depend on your own kernel settings.

If it still fails, it would be a memory timing (see the BIOS) or memory failure..   or (unlikely) some problem between software and your chipset ?

Since memtest86 finds no problems, the memory modules may be good. The problems may be timings, or other intermittent problems. I think you should try the lowest memory frequency, and max timings, in the BIOS..  And also, try removing one memory module !

And every time you change something in the BIOS, write it down...  so when memtester is finally stable, you can see which "magic" setting helped  :Very Happy: 

If really nothing works (even at low frequency and relaxed timings), try other memory modules..

Good luck !

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## Terrax

Thx a lot. That was my plan, if no one could come up with a specific "software" reason  :Smile: 

I think its maybe some kernel options (IOMMU), which can be the problem. I have compiled my whole system with that option enabled. And now I have it disabled, begause I had to disable agpgart. Maybe I should try enabling that again.?

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## Terrax

By the way. The funny part in the faults in memtester, is that they only appear common if the computer have done something stressing with me memories. Example decompressing. But I know it isn't a heat issue.

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## Terrax

Ok I think I have found the problem.

When I changed back to single channel mode memory, there were no faults at all. But could it really be the dual mode, which doesn't work with my two identical memory blocks? I have runned windows for a long time without problems (Though it was 32 bit.)

So could it be? That memtest86, use a 32bit way to test the memory, and didn't find any problems. Memtester use 64bit enviroments, to test the memory and did find problems. So for me it is not possible to run dual channel memory in 64 bit enviroments? Does that make sence? Plz any memory specialist take a look on this issue  :Smile: 

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## numlock

Great that you found the cause  :Very Happy: 

I'm not an Athlon64 memory expert. Maybe the access patterns are very different between 64-bit and 32-bit modes, so 32-bit doesn't trigger the problem (or less often). Or maybe Windows and NTFS filesystem don't expose all RAM problems (remember, unpacking big tarballs in linux is a very good RAM and filesystem test...).

Anyhow, memtest86 doesn't find the issues, because it's focused on finding specific bad memory cells. It seems all your memory cells are fine.

Perhaps dual-channel imposes more strict timings on the memory chips.. or maybe there's some bug in dual-channel support with your chipset ?

Just curious: is dual-channel supported by the Athlon64 chip ? Or is it a motherboard thing ?

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## Terrax

Thx for the fine answer  :Smile: 

 *Quote:*   

> 
> 
> Just curious: is dual-channel supported by the Athlon64 chip ? Or is it a motherboard thing ?
> 
> 

 

Its a motherboard thing. Your motherboard has to support it (The nforce series I think is the only platform, which does).

But your cpu has to too. Don't kill me if Im wrong, but as far as I know. The Athlon xp series does support the dual channel, but the newer amd64 130 nm doesnt. But the newest amd64 90 nm does.

I don't know about pentium cpu's, if they does support it or not. And I wonder if nforce chipset supports pentium at all?

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