Description of problem: Very large files are corrupted when written Version-Release number of selected component (if applicable): How reproducible: Very easy on my system (uname -a): Linux liv.local 2.6.25.10-86.fc9.x86_64 #1 SMP Mon Jul 7 20:23:46 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux Steps to Reproduce: 1.Run this shell script: #! /bin/csh set count = 10000000 @ count = $count / 2 dd if=/dev/zero of=zerofile count=$count echo 1 md5sum zerofile echo 2 md5sum zerofile Actual results: (Results vary) 1 bd14343288d1a834bfb0ae933bf8e4b6 zerofile 2 81096f2d72f4b010f8cc8f6c7b19b812 zerofile Expected results: The output of the first md5sum and the second should be the same but they are not. 'sum' shows the same problem. Additional info: No data errors are report in /var/log/messages. I started seeing this problem on Fedora-8 but only on very large files (in the above case the file size is 2.4G). The folllowing C program reports the corruption in the above file (0x00 bytes that becomes a 0x80 bytes) #include <stdio.h> FILE *f; unsigned char b[4096]; int i; int n; int total; int main(char *argv[], int argc) { f = fopen("zerofile","r"); if (f) { total = 0; while ((n = fread(b,1,sizeof(b),f)) > 0) { for (i = 0; i < n; i++) { if (b[i]) { printf("%d (0x%x): 0x%x\n",total,total,b[i]); } total++; } } fclose(f); } } Sample output: 1149587513 (0x44855039): 0x80 1149587545 (0x44855059): 0x80 1149587577 (0x44855079): 0x80 1149587641 (0x448550b9): 0x80 1149587673 (0x448550d9): 0x80 1149587769 (0x44855139): 0x80 1149587801 (0x44855159): 0x80 1149587897 (0x448551b9): 0x80 1149587929 (0x448551d9): 0x80 The drives are Seagate SATA 500 G drives. I've had problems with two different drives---one was attached via a USB enclosure and one is internally attached via SATA. Both were connected via the logical volume mechanism (different lv's, though). Lastly, I've not seen a file < 1GB have a problem though I haven't run the above script intensively on smaller files.
not reproducible here. 0x0 > 0x80 is a single bit flip, which is sometimes indicative of bad memory. You might want to try running memtest86 for a while.
Memtest86 indicated errors in both memory DIMMs. I swapped them out and there are no errors when I copy large files. Thanks!