May 29, 2021, 6:09 PM
Post #10 of 16
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On 5/29/21 5:42 PM, thelma@sys-concept.com wrote:
>>> Another mystery.
>>> I copied the file to USB 1TB sandisk.
>>> md5sum check OK same as my computer
>>>
>>>
>>> md5sum /run/media/joseph/SSD-1TB/business/backup/VDI/windows-7_pro_May-23-21.ova
>>> 6f3348f1fb915af9c45806d947558a37 /run/media/joseph/SSD-1TB/business/backup/VDI/windows-7_pro_May-23-21.ova
>>>
>>> I mount the same USB 1TB sandisk on another computer and running md5sum on same file gives me different number, why???
>>>
>>> md5sum /run/media/fd/SSD-1TB/business/backup/VDI/windows-7_pro_May-23-21.ova
>>> c478cb48e2f7961cb0e3eb452df6e642 /run/media/fd/SSD-1TB/business/backup/VDI/windows-7_pro_May-23-21.ova
>>>
>> Did you sync and unmount the partition before ejecting the drive from
>> the first computer? With a file this large being copied, it is likely
>> that a large amount of data remains buffered/cached and will not be
>> fully written to the flash memory even after the copy command completes.
>>
>> On the first machine, you would still see the correct md5sum because the
>> kernel abstracts this fact away from you. But if you rip out the drive
>> and take it somewhere else without flushing those caches, you're going
>> to get an incomplete file.
>>
>> Check if the file on the drive still md5sums the same if you plug it
>> back into the first machine. Check what size it is, and whether there
>> are a lot of 0s at the end indicating an unfinished write.
>>
>> cal
>
> Yes, I unmounted the USB device every time.
> And yes, I plug the USB device back to original machine and md5sum is correct, same as the original.
>
> I copied the large file over network to another box and md5sum of: windows-7_pro_May-23-21.ova is correct same as on the original box.
>
> I run this: "rsync -avh [source] [destination] && rsync -avhc [source] [destination]"
>
> above code rsync files folder on first run and if complete without issue, will run rsync again immediately while performing same file name comparison by using hash of entire file.
>
> This i what I got:
>
> rsync -avh windows-7_pro_May-29-21.ova fd@10.0.0.138:/home/fd/business/VDI/ && rsync -avhc windows-7_pro_May-29-21.ova fd@10.0.0.138:/home/fd/business/VDI/
> sending incremental file list
> windows-7_pro_May-29-21.ova
>
> sent 30.29G bytes received 35 bytes 115.81M bytes/sec
> total size is 30.28G speedup is 1.00
> sending incremental file list
> windows-7_pro_May-29-21.ova
> WARNING: windows-7_pro_May-29-21.ova failed verification -- update discarded (will try again).
> windows-7_pro_May-29-21.ova
> ERROR: windows-7_pro_May-29-21.ova failed verification -- update discarded.
>
> sent 33.44M bytes received 6.47M bytes 123.38K bytes/sec
> total size is 30.28G speedup is 758.62
> rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1330) [sender=3.2.3]
>
>
>
rsync is emitting errors indicating the file was not transferred
correctly. At this point I would call into question whether your second
machine is the problem rather than any of the tools you're using. If
you have a third machine that is easy to test. Otherwise I would run
memtest86+ and smartctl.
cal