The process is pretty straightforward once you're used to it, and in less than three hours I was ready again to import my first template (a template I had imported before). But now, I submit the the request, and almost immediately the process aborts. (You can see in the information below, that 1 second passes between the Import request (06:32:36) and the failure.)
Thing is, it takes about three minutes, even locally on the web server, to get an index of that large file (tar tzf), and at completion, the vm config file is listed.
Am I misreading the error? My web searches for enlightenment found only one good hit on this error, and in that case it appeared to be an "out of space" issue. In this case, though, I'm importing a 5GB tarfile into a 390GB, otherwise-empty file system, so I don't think that is the issue. The failure in ovs-agent.log is below. What other information may I provide to get to the bottom of this? (Thanks for any guidance/help, of course!)
The above problem is solved. There are two web servers at play here: http://aspire and http://aspire1. Only aspire1 had the file in question, so IMPORT request was receiving a 404 page, and of course found no config file within that.