What is my bottleneck when cloning a git repository from a virtual machine with a fast network connection?

Question

I have a situation with a relatively large git repository located in a virtual machine on an elderly, slow host on my local network where it takes quite a while to do the initia

Answer 1

After realizing that the upper limit to the transfer speed of data, is the ssh connection which is established "outside" of git I did some experiments, and found that the upper limit of using pcsp (Putty scp) was 3,0 MB/s as the blowfish encryption scheme was properly chosen. A control experiment with raw ftp showed that the transfer speed was 3.1 MB/s, so it indicated that this was the upper bound of the network.

This runs inside a vmware hypervisor, and as the process doing network I/O utilized almost 100% cpu it indicated that the bottleneck was the Ubuntu network card driver. I then found that even though vmware tools were installed, for some reason the kernel still used the vlance driver (emulating a 10 MBps network card with IRQ's and all) instead of the vmxnet driver (which speaks directly to the hypervisor). This now awaits a service window to be changed.

In other words, the problem was not with git but the underlying "hardware".