Test your iCloud

Cirrus provides a small, standardised test involving the copying of a 1 MB file from local storage (in ~/Library/Preferences/co.eclecticlight.Cirrus.data) to your iCloud Drive. This is ideal for observing the transactions which take place in the iCloud subsystems and services, and should help diagnose problems.

To run the test, ensure that you can see a Finder window in which the iCloud progress icon will be visible. Then click on the  Copy to iCloud  button in any document window, and watch that progress icon.

Cirrus then creates a 1 MB test file consisting of the byte  0x88  repeated throughout and saves it to ~/Library/Preferences/co.eclecticlight.Cirrus.data. The app next checks to see if there is already a test file in your iCloud Drive, at ~/Library/Mobile Documents/com~apple~CloudDocs/co.eclecticlight.Cirrus.data. If there is, that is deleted.

Cirrus then tries to copy the test file from ~/Library/Preferences/co.eclecticlight.Cirrus.data to ~/Library/Mobile Documents/com~apple~CloudDocs/co.eclecticlight.Cirrus.data, which should then appear at the top level of your iCloud Drive folder.

Observe when iCloud’s progress icon completes and disappears, marking the end of the copying process, and compare that time against the time saved to the  End  boxes. In the great majority of cases, the actual completion of copying occurs well before the time set in the  End  boxes, and you won’t need to adjust that. If copying were to take longer, adjust the  End  time to a few seconds after its completion. If you make the interval between  Start  and  End  too short, less than about 30 seconds, some log entries may be omitted.

Once copying is complete, you can click on the  Clean up  button, which removes the two copies of the test file.

Once the test copy is finished and you are happy with the  Start  and  End  times, and ensuring the the real clock time is now later than the  End  time, click on the  Get log  button to view the log during the copying process.

You can also perform a manual test, in which you drag-copy a file to your iCloud Drive, and set the  Start  and  End  time according to your Mac’s clock. You can use a similar technique to assess log entries when saving a document from an app to iCloud, or for any other function that you wish, although you will have to enter  Start  and  End  times manually for those.

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