First, the problem that made me think of this. Then the suggestion.

Yesterday BOINC started uploading the last WU for a climateprediction.net task. At the end of the upload I get this message:

6/28/2012 08:18:13 | climateprediction.net | [error] Error reported by file upload server: can't write file /storage/cpdn-restarts/incoming/uploader/hadam3p_pnw_b4dp_1997_1_008003418_1_13.zip: Input/output error

My guess is that the server's HD was full and the file couldn't be written onto it. As a result the file would wait a bit and then start again. Problem was it would use up quite a bit of the bandwidth on my wireless network to upload the file. The it would get to the end, fail, and start over. This created a bit of a problem in using my network. I wasn't about to abort the transfer, it being the last on the run and all. The only solution I found was to shut-down BOINC. Not exactly what I wanted to do, even though it doesn't run while I'm active on the computer.

So the suggestion, under the transfers tab there should be a third command, "Pause Transfer". I admit I'm not a programmer so I've got no idea if this would be difficult to do or not, but this is only the most recent time that I've wished I had such a button to stop an upload that was hogging bandwidth while I was trying to work.

Hopefully I posted this in the right spot, and that this is something the development team will consider. Thanks for your time, Oh, and that file finally went up just a bit ago so at least that's something.

Hi, and welcome to the board. Yes, this is a good place to make suggestions like that - though you may find it takes a long time for them to be acted on.

You are right to suspect a full hard disk as a possible cause of the problem, though the actual detail was slightly more subtle. The server handling the actual upload was fine, but it was supposed to transfer the completed file to a second server after the upload was complete - and the Climate Prediction project was close (too close) to the limit of what they were allowed to store on that second server.

BOINC will detect that the upload server is full, and refuse to accept more uploads until the administrators have dealt with it: but BOINC doesn't (yet) detect the quota problem on the offload file storage, which is why it continues to accept the files, but reports (32 MB later) the error you have quoted. If it's any consolation, one of my files uploaded 10 times overnight, with an error each time, until a successful eleventh upload this afternoon. Fortunately, I'm on a wired connection, with no bandwidth cap or surcharge, but I can see that this problem could be an irritation, and possibly an expense, for some people.

CPDN will be working behind the scenes to try and prevent this happening again, but that may take a little while. If it happens again, and you happen to be near the computer at the time, there is one BOINC feature that you could use without shutting down BOINC completely.

Go to the BOINC Manager's "Advanced" view, and from the "Activity" menu, choose the very last option: 'Network activity suspended'. That will stop BOINC trying all file transfers - uploads and downloads - until you choose another option.

There are two problems with that: firstly, it blocks communications for every BOINC project you may be running, not just the one with the faulty server: and secondly, you have no way of knowing when the problem is solved, except by re-enabling network activity, waiting until the file has uploaded, and looking to see if the error message is shown again.

We did, a long time ago, make a request very similar to the one you describe - ticket [trac]#139[/trac]. Unfortunately, the 'powers that be' were unsympathetic then, and they show no sign of softening their attitude now - but no doubt this latest episode will encourage another attempt.