Slightly OT: local network bandwidth - upload vs. download

Rocky Linux Tech Help
1

Hi,

In my local network I have a sandbox PC, a battered Dell Optiplex 3020 with a core i5 processor and 8 GB RAM that I’m using to test all the stuff that requires bare metal and can’t be tested in a VM (KVM, Proxmox, etc.) The sandbox PC sports a small 60 GB SSD disk.

Besides this I have an equally battered Synology NAS running an FTP server for the local net. This NAS has a single purpose: host various Ghost images from the sandbox machine.

Let’s say there’s a custom Rocky Linux 8 install on the sandbox PC. Once I’ve done all my testing, I want to backup this installation. Usually I’m running the following command within the system to zero out everything on the disk that is not the installation itself:

# dd if=/dev/zero of=/0bits bs=20M ; rm -f /0bits

Once this is done, I boot G4L (Ghost4Linux) and transfer the contents of the sandbox PC to the FTP server on the NAS, bit by bit in a filesystem-agnostic raw mode. I’ve done this for years and it really is a no-brainer.

On my NAS I have a series of images, each a handful of gigabytes in size:

  • rocky-8-srvbase
  • rocky-9-srvbase
  • rocky-8-desktop
  • rocky-9-desktop
  • windows-10
  • proxmox
  • etc.

This setup has been working perfectly for more than a decade now. Except there’s one detail that’s nagging me.

When I boot up Ghost4Linux on the sandbox PC and backup my Ghost image to the NAS, uploading all this is relatively fast. Displayed bandwidth is around 150 MB/sec. Whole process takes around 5 minutes.

On the other hand, when I want to fetch a Ghost image from the NAS and install it to the sandbox PC, downloading the Ghost image is painfully slow, somewhere around 10 to 20 MB/sec. Whole process takes about an hour to complete.

I’m not a network expert, so I’m a bit clueless here. Any idea if there is something to be done here to improve download speed?

Cheers,

Niki

2

Have you checked your small SSD on your sandbox PC? Is it worn out? I suspect if it was worn out after many years of usage.
To test out, you may install smartmontools, and test your drive with smartctl

sudo yum install smartmontools
smartctl -t long /dev/sda
smartctl -a /dev/sda
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