Description of problem:
Current guide proposes PowerShell script to verify checksum under windows, that requires to load the whole image into the memory. This is not ideal and might fail on systems with less RAM.

Version-Release number of selected component (if applicable):
fc23 so far

How reproducible:
on systems with not-enough available RAM

Steps to Reproduce:
1. run proposed commands from guide [1]

Actual results:
this might fail:

    $download_checksum = [System.BitConverter]::ToString($sha256.ComputeHash([System.IO.File]::ReadAllBytes("$PWD\$image"))).ToLower() -replace '-', ''


Expected results:
should work more effective:

    $stream = (Get-Item $filename).OpenRead()
    $hash = $sha256.ComputeHash($stream)
    $stream.Close()
    $download_checksum = [BitConverter]::ToString($hash).ToLower() -replace '-'

Source [2] with license:
 under cc by-sa 3.0 with attribution required


Additional info:
[1] https://docs.fedoraproject.org/en-US/Fedora/23/html/Installation_Guide/sect-verifying-images.html
[2] http://stackoverflow.com/a/35116369/2196426