impression operations manual

previous

Previous Page

table of contents

Table of Contents

next

Next Page


How is Impression's estimate for needed scratch space computed?

The formula that Impression uses to compute necessary scratch space depends on the options chosen for a backup operation, and also on the list of files selected to be backed up. Here's a rundown of the various formulas and when they'd be used:

    Using disk images as the backup media:
    Scratch space = (estimated total backup size + computed file system overhead based on file count + additional 6% for catalog)
    (Enforced minimum scratch size = 10MB)
    Using CD/DVD as the backup media (when the largest file can be found):
    Scratch space = (CD/DVD disc size + largest file size in backup)
    Using CD/DVD as the backup media (when the largest file cannot be found, or when it exceeds 2 x the disc size):
    Scratch space = (CD/DVD disc size x 3)
    Burning cross-platform compatible, hybrid HFS+/ISO9660/Joliet discs:
    Add 1x the disc size to the above calculations

ImpsAnswer 105, last modified: 2006.02.06


© Copyright 1998-2006 Stephen W. Elliott, All rights reserved.