On 5/29/21 1:32 PM, the...@sys-concept.com wrote: > On 5/29/21 2:00 PM, Mark Knecht wrote: >> >> >> On Sat, May 29, 2021 at 12:54 PM <the...@sys-concept.com >> <mailto:the...@sys-concept.com>> wrote: >>> >>> I use "scp" to copy large file over local network, windows-7_pro.ova (about >>> 28GB) but I it failed to import the appliance with VirtualBox. >>> Checking the md5sum of the source and destination it turn out they are >>> different. >>> >>> Is "scp" reliable for large files? >> >> In my experience scp is reliable but for large files I'd probably opt for >> some version of rsync, possibly the -P option. That way if the transfer >> stops for some reason you can generally pick up where it left off. >> >> HTH, >> Mark > > 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
