Re: [SOLVED] [gentoo-user] is "scp" reliable?

On 5/29/21 7:09 PM, cal wrote:
> On 5/29/21 5:42 PM, thelma@×××××××××××.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

Right On Cal, running memtest86+ gave me nothing but errors.  I'm surprised it compiled all the packages recently without any errors.
Putting two good stick in it and md5sum worked without a problem.   
Was able to import OVA into virtualbox without any errors.