My question in short: is there a tool that copies a file from directory A to B while, simultaneously, generating the checksum of the file it has copied/read, without doing an extra read/pass just to generate the said checksum?
I will be copying a few TBs of files from one HDD to another and instead of:
- Copy files from HDD1 -> HDD2 (X hours)
- Generate checksums of files on HDD1 (Y hours)
- Verify checksums of files on HDD2 (~Y hours)
I was thinking of a more streamlined process:
i. Copy files from HDD1 -> HDD2 and generate checksums of the files copied as well (Z hours) ii. Verify checksums of files on HDD2 (~Y hours)
My assumption is that Z ~= X because the program that can so this will have read the complete file (as it's copying it from one HDD to another) and hence does not need to read the file again just to generate its checksum.
Now I know this idea of mine might not work, if for example, the OS uses DMA to copy the file, and I am not sure what technique Windows 7 uses to copy files from one HDD to another.
Any suggestions to this effect will be appreciated - specially speeding up the copying process and making sure the transfer is 1:1 without corruption or missing files.