md5sum sha1sum are different after copy file/s by cp command, krusader or nautilus
Hi,
I have a problem when I made copy of big file/s. I have been trying to check their md5 and sha1 (md5sum -b file.vdi , sha1sum -b file.vbi) but copied file differs against the original file. Files are copied between ext4 partitions. I have tried to copy file by cp command, krusader or nautilus - it has always different md5 or sha1. Could anybody please explain what am I doing wrong and what should I do that copied file should have same content ? thank you. |
This behavior can be caused by hardware failure, I would recommend to check the health of the RAM (using Memtest86+) and the disk(s) (using the manufacturers diagnosis tool).
Something like that may also be caused by a not stable running overclock, does your system run within its specs? |
Hi,
Thanks for quick reaction. I have checked before many times memory by memetest86+ - it is ok according to this test. I have many SATA III/II hard drives but in windows 7 this errors does not exist even if I made copy from different partition/s BUT between same disk/s even if partitions are ntfs. And this behaviour is only with files bigger that tens of gigabytes (vrtualbox vdi files). When copy ISO files ( up to 4.7Gbytes) - it is correct with nautilus but it is not correct with krusader for same files, cp terminal command I did not check so many times md5 or sha1 so I cannot say for now. I did no check all hard drives which I am actively using with manufacturer diagnostic tools yet because those disks are correct in windows. So , I am not assuming that only ext4 or btrf partitions have problems and ntfs partitions are correct on the same hard drives :-) . But I am going to try it some night/s. According to those it seems to be only problem because of overclock. I have maximus iv extreme R3, i7-2600k(3.4GHz) - OC:5.1GHz , memory OC:1600MHz , 9-9-8-24-1 - it should not be problem , graphic card is not OC. Which is strange as well because win764bit works more or less properly - not with such problems (have another :-( ). P.S. would it be possible that antivirus is doing this things (I have avg and clamav) ? (Hope it is not some kind of malware ) |
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Unfortunately sha1 is different by using dd ... AND I have done sha1 on the same file and ... result is different: $ time sha1sum -b file-ubu1.vdi daef63a16afaaf4ef7cf596f62c528d543597739 *file-ubu1.vdi real 6m9.180s user 1m45.150s sys 0m10.450s :-) 2.02 1.97 1.71 1/713 6384 pts/2 jobs=0 16:32:22 /home/_virtual.readANDwrite u1@PCEUBU1 1:2006:7 $ time sha1sum -b file-ubu1.vdi 582acf68f271e44540c5bb5e94ed22694ebad1df *file-ubu1.vdi real 6m6.380s user 1m47.040s sys 0m9.620s Now I am completely confused. Does journaling of ext4 or file caching doing this ? Can anybody explain what I am doing wrong ? thank you for any hint. |
I forgot to mentioned that I used:
dd if=/dir/to/source-file/file-ubu1.vdi of=/dir/to/dest-file/file-ubu1.vdi and dd bs=1G oflag=dsync,sync,nocache conv=fdatasync,fsync if=/dir/file of=/dir/file file has 47 Gbytes. sha1 is different. |
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Try it again without the overclock and see if that works. If it works your overclock is not stable and causing your issues. |
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I have checked sha1sum of tens of .ISO files and .vdi files - NOT COPIED. It looks like files bigger than 3.8(3.9)Gbytes have always different sha1 result measured by sha1sum. |
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# real 6m6.380s # user 1m47.040s # sys 0m9.620s the worst result: # real 10m52.592s # user 1m55.320s # sys 0m10.430s |
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I have tried to use groovy (version 1.7.4) source code taken from: http://groovy.codehaus.org/Calculati...or+large+files and I tried openssl sha1 file.vdi (version OpenSSL 0.9.8o 01 Jun 2010) and guess what ? It behaves exactly the same way (sha1sum or sha1deep) as I described: for files bigger than ~4Gbytes it had different sha1. I did not copy files - just repeat the same command on same file. |
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I do not have to copy file, It have happened if I run twice or more times same check-sum command on the same file. File has to be bigger than approximately 3.9 (3.8-4.2) Gigabytes. Tested with sha1sum -b , md5sum -b , sha1deep , md5deep , openssl sha1 , groovy sha1 algorithm. I made test on four EXT4 partitions - they are located on 4 different hard drives (2 external and 2 internal HDDs/USB flash drive) on one computer (other 3 computers does not have this issue). NTFS partitions DO NOT have these check-sum problems measured on the same hard drive where is located ext4 partition as well (3 HDDs). ... (This I assume eliminates possibility of hardware error/s of hard drive/s) On BTRFS partition it is not possible to check because of I/O problems: md5sum -b ubu1104.vdi # md5sum: ubu1104.vdi: Input/output error openssl sha1 ubu1104.vdi # Read Error in ubu1104.vdi # 5210:error:0200B005:system library:fread:Input/output error:bss_file.c:202: # 5210:error:20082002:BIO routines:FILE_READ:system lib:bss_file.c:203: sha1sum -b ubu1104.vdi # sha1sum: ubu1104.vdi: Input/output error Run sha1sum from live-cd ubuntu 11.04 64bit have same results. No overclocking. Tested on linux kernel from 3.0.1 to 3.0.4 versions compiled by myself with ubuntu patches, config changes only core2 and mtune=native march=native tested on (3.0.0-8 - 3.0.0-12 kernels compiled by ubuntu team) I have no idea what causing this issue? Could it be some kind of malware ? Please any help , advice I really much appreciate. Thank you, |
Check your harddisks with the manufacturer's diagnosis tools, also have a look for harddisk errors in the logs.
If it is not the disks and not the RAM and also happens with different versions of Linux I would assume that it is a hardware error, reseat all cables, maybe replace them, if that doesn't help I would think it is some serious failure, maybe motherboard or CPU. |
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but how you can explain that it DID NOT happened on ntfs partition ? but happened only on ext4 partitions ? it is the same command , same hard disk , same file but located on ntfs partition. how it could be hardware failure ? this is what I do not understand ... . |
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