GUI Option to set zsync as default

Hi Vish,

Thank you for reporting bugs. I do have a few questions though:

When using rsync, do you mean that it starts from 0% in the GUI?
How do you know it actually downloads the whole ISO (700mb) instead of only what has changed? How have you tested this?

I'm asking this because when downloading a, i.e. 2 day old ISO, the percentage that TestDrive GUI shows will always start from 0, to 100, regardless of whether it is downloading ~100mb, ~200mb, etc, or the ~700mb of a complete ISO. If you wanna see the different, you might wanna do the following:

1. System > Administration > System Monitor
2. Under Network History, check Total Received.
3. Start syncing an ISO that's 2 days old. Wait for it to finish and see the "Total Received" filed mentioned above.
4. To compare, do the same with an ISO that's not been previously downloaded. You will then see the difference.

However, I'll consider giving the option to select zsync as an alternate sync method in the future.

Best regards.

Even before the GUI was available, why i thought it re-downloaded the whole 700mb each time was since i notice :
a file ~/.cache/testdrive/iso/.ubuntu_natty-desktop-i386.iso.k2uD6e (the last "k2uD6e" is random as you would already know) gets created first with 0 bytes everytime(i have nautilus configured to display the filesize)
 and then once it reaches 700mb it overwrites/replaces the ~/.cache/testdrive/iso/ubuntu_natty-desktop-i386.iso
And it takes(or seems to) a lot longer than zsync. I dont recall seeing it update the iso quickly.

However, since these are not really accurate measurements, I'm updating the iso again today and I will be checking with sysmonitor how it goes with both the zsync/testdrive(rsync?) and will file a separate bug with info.

Bah!! I was completely wrong.. (unless you guys secretly, magically updated testdrive with no version updates ;p )

The download amount does not match the ~700mb. The amount that had been downloaded was lesser .
I seem to have been mislead by how the two work differently.
Testdrive starting at 0% and the file size count starting at 0 is a bit confusing.
The reason this is misleading is, because, 0% --> 100% time will *never* be the same. Since it seems to be secretly syncing and then recording the percent complete of the file.

But it might be better if testdrive gave the actually amount of sync progress. (like how we notice in zsync.)
 This would give us a better estimate of the time left to sync rather than a sync which takes random amount of time.
Is this a limitation of rsync? And would it be fixed when we have this zsync option ?
Or should i file a separate bug requesting better sync progress reporting?

Vish,

Indeed the starting at 0% might have been misleading but unfortunately this is given by rsync itself. The thing is that when rsync starts "updating" and ISO, it starts from 0 to XX (in let's say 10 seconds), where XX will be the percentage that is already downloaded, from that point, it will start moving from XX to 100% (in the time it takes to download that percentage left).

Because of this, it *seems* that rsync is downloading a new ISO completely when it is not. It is just updating the ISO. For this reason it is why testdrive will always show from 0 to 100%.

And yes, this is a limitation from rsync, and to tell you the truth, using *zsync* causes the progress to change depending on what step it is downloading, and it is not always accurate. But you can still use *zsync* though.

To do this, just do to the "Other" tab, and click on "Add ISO" and in the new dialog, add the URL of the ISO you wan't to download and select zsync as downloading protocol

Either way, I personally prefer rsync. You don't need to file another bug!

Best regards,

Ah! I dint realize we could use the 'Other' tab for this. Thanks!
I tried it and noticed what you mention; it does indeed seem confusing.
As you mentioned, testdrive+rsync might be clearer. :-)