I’m currently watching the progress of a 4tB rsync file transfer, and i’m curious why the speeds are less than the theoretical read/write maximum speeds of the drives involved with the transfer. I know there’s a lot that can effect transfer speeds, so I guess i’m not asking why my transfer itself isn’t going faster. I’m more just curious what the bottlenecks could be typically?

Assuming a file transfer between 2 physical drives, and:

  • Both drives are internal SATA III drives with 5.0GB/s 5.0Gb/s read/write 210Mb/s (this was the mistake: I was reading the sata III protocol speed as the disk speed)
  • files are being transferred using a simple rsync command
  • there are no other processes running

What would be the likely bottlenecks? Could the motherboard/processor likely limit the speed? The available memory? Or the file structure of the files themselves (whether they are fragmented on the volumes or not)?

  • archomrade [he/him]@midwest.socialOPEnglish
    4·
    8 months ago

    SATA III is gigabit, so the max speed is actually 600MB/s.

    My mistake, though still, a 4tb transfer should take less than 2hr at 5Gb/s (IN THEORY) Thank you @Max_P@lemmy.max-p.me for pointing this out a second time elsewhere: 6Gb/s is what the sata 3 interface is capable of, NOT what the DRIVE is capable of. The marketing material for this drive has clearly psyched me out, the actual transfer speed is 210Mb/s

    The filesystem is EXT4 and shared as a SMB… OMV has a fair amount of ram allocated to it, like 16gb or something gratuitous. I’m guessing the way rsync does it’s transfers is the culprit, and I honestly can’t complain because the integrity of the transfer is crucial.