Pagefile & Hiberfil save vs skip

[chrisj]

Using the WinPE recovery disk created from HDM Suite 2011, I backed up my Windows7 test system with 3 scenarios: 1-skip the page & hiber files; 2-don't skip them; and 3-both files deleted completely (recycle bin empty).

The resulting archives for all 3 scenarios were approximately the same sizes. Specifically, as follows (actual size, not 'size on disk'):
Skip: 7,420,976,537 (6.91g) source size 13.4g
Don't skip: 7,418,175,677 (6.90g) source size 13.4g
Files deleted: 7,421,080,829 (6.91g) source size 11.7g

Notice that the 'don't skip' was the smallest, while the 'deleted' was the largest.
System restore was turned off during all scenarios.

Pagefile was 1gig, Hiberfil was 761meg.

All other backup settings were default, and archives were sent to another local hard drive.

WHY????

Chris

[Robin A.]

According to these results, it seems that when the images are created from WinPE, there aren´t OS auxiliary files in the disk. Perhaps these files are deleted or emptied when Windows shuts down or the computer reboots, and re-created when Windows loads.

What results do you get when imaging from within Windows?

[chrisj]

Robin A:
The files ARE there, and they are in the archive, for both 'skip' & 'don't skip'.
Same results when doing it in Windows.

[cincinnatijack]

The files names are in the archive but they are empty (Size 0), this is done internally and can't be controlled or changed by the user.

[Robin A.]

Another possibility is that the option doesn´t really have any effect and the files are always skipped. In other imaging programs, these files are skipped by default and there isn´t any option to keep them. Examples are O&O DiskImage Pro and ShadowProtect.

[chrisj]

Ok, it's obvious the option has no effect, which begs the question: why bother? Seems to me the object of skipping them is to reduce the size of the archive. Even if the contents are not saved, by keeping the size definition, the archive size is not reduced. (run time didn't change either)

But that does not explain why, when I deleted the files and verified that they're gone ('used' space decreased by the amount of the files), the resulting archive was larger than with the other 2 scenarios?

[cincinnatijack]

Originally Posted by chrisj

Skip: 7,420,976,537 (6.91g) source size 13.4g
Don't skip: 7,418,175,677 (6.90g) source size 13.4g
Files deleted: 7,421,080,829 (6.91g) source size 11.7g

The archived file with the Files deleted was larger by only 0.01g (6.91g vs 6.90g), this is rounding error and it applied to only the Don't Skip.

[Robin A.]

Yes. The differences in size are too small to be significant.

[chrisj]

Yeah, 3m (.01g) isn't much, but that's not the point. My point is, that with the files deleted (note the 'source' is 1.7g smaller) that the archive should have been much smaller, not 3m bigger.

The amounts in my case are not significant, having only 1g of RAM. On a machine with larger amounts of RAM it could be significant, particularly if the user wants to back up to dvd's. In my case, since I back up to a hard drive, and I'm only doing this on a test system, I don't really care at this time. Just trying to understand why a smaller source yields a bigger archive.

I have now tried another scenario. I added an exclusion category, and specified the 2 files (pagefile.sys & hiberfil.sys), and now get the expected reduction in archive size.

1. 'skip' & 'exclude' archive size 6.82 (WinPE)
2. 'skip' , 'exclude', and files deleted, archive size 6.80 (WinPE)
3. same as #2, but in Windows 7, archive size 6.7