upload of a ~2GB virtual machine image
On ADSL lines, given that the rate of upload will only be up to ~100KB per second, it is going to take at least 20000 of those seconds.
If the upload is via a web-based form you can't guarantee it will complete if it takes longer than 15-30 mins (the session may timeout).
An FTP client that can resume an upload may do better but you have to accept this can a good chunk of your day, and you may prefer to limit the upload in the client to 80% of what is available (otherwise your downstream and latency may also be affected).
(edit) FileZilla can do this, and can talk to both FTP and SSH servers.
Even if you get a 2Mbit upload it is probably going to take longer than 3 hours.
This is where you need to consider different class of internet connection rather than bonding 2 lines.
If you were regularly exchanging virtual machine images, with only small progressive changes, something to look at is
rsync which can send differential files rather than the whole thing. I believe
Dropbox is based on this too.
or
with virtual machines, depending on the nature of the project, it is feasible to place the (changing) data on a separate smaller disk image from the operating system, if you only need to exchange that (and maybe a tar.gz or zip of any configuration folders (such as /etc).
prompt $P - Invalid drive specification - Abort, Retry, Fail? $G
prlzx on iDNET: ADSL2+ / 21CN at ~4Mbps / 700kbps with IP4/6
Edited by prlzx (Thu 02-May-13 22:23:20)