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Check if there's enough drive space for an upgrade before downloading an image
Closed, ResolvedPublicBUG


Ever since the first Vyatta versions that supported image upgrade (that's 6.0/Larkspur for the curious), when a user runs add system image, the update script:

  • Downloads the image without caching it.
  • Checks if there's enough space for the upgrade.
  • Performs the upgrade.

This is alright if there's enough drive space for the upgrade. If not, it's:

  • Annoying because you need to repeat the procedure.
  • Time-consuming on slow links.
  • Expensive on metered connections.

Checking free space _before_ downloading would be a big UX improvement in that case.

We can do it the following way:

  1. Try an HTTP HEAD request for the image URL.
  2. If that request succeeds and returns a Content-Length header, then calculate the required space precisely based on that data.
  3. If there's no Content-Length in the response (or the protocol doesn't have an equivalent of HEAD and Content-Length), then use some heuristic, e.g. 500M, and do a precise check after the image is downloaded.


Difficulty level
Normal (likely a few hours)
Why the issue appeared?
Will be filled on close
Is it a breaking change?
Perfectly compatible
Issue type
Improvement (missing useful functionality)

Related Objects

Event Timeline

erkin changed the task status from Open to In progress.May 6 2021, 7:54 AM
erkin triaged this task as Low priority.

install-image now calls a routine that queries the size of the remote file and aborts if there isn't enough space to download the image.

SrividyaA set Issue type to Improvement (missing useful functionality).Aug 31 2021, 3:39 PM