Defrag and incremental backups

Hi all,

I just made an incremental image after some minor changes to the system (adding registry keys, changing group policies, defragmentation). This incremental image is even bigger (1.3GB) than the underlying full backup (1.2GB)!

PeterFoxTI has written in a previous thread that True Image 7.0 has this problem.

• Does this problem still exist in version 9.0?
  (or is there some solution to overcome it ? (e.g. using another defrag tool))
• Do other imaging tools perform better?

Thanks for your help
JothiS

 

The backup files will be larger if you defrag the source files.
This is stated in the tI user's guide.
Indeed, Acronis suggests that, after doing a defrag on the source drives, a FULL, not incremental, backup be created.

I expect this behavior will be the same for all "image" based backups.

 

AFAIK, TI is concerned with sector changes, not changes to files. Even if you make no changes to the files, when you defrag the sector layout can undergo a major change. This is reflected in the size of an INC backup file.

 

Thank you for your answers So, this feature is not really useful in daily work (at least for me). Who wants to abandon defragmentation?

Before I made my system updates and the incremental backup, I had restored the full backup. Perhaps TI does not restore the sectors at their original place, what would definitly lead to a big incremental backup file. I observed data consolidation, when I restored an image on a second partition (PS: TI had no reason to consolidate my data, because the last used sector was within the partition limit)

If TI does consolidate data during restoring, it would outsmart itself.

 

I just tested it. TI DOES consolidate data!

IMHO the following scenario would lead to a big incremental:
- Full backup of a fragmented partition
- Restore this backup
- Optional: Some minor file changes
- Incremental backup

Defragmentation with a tool that consolidates data (MS Defrag does not really do it) before the full backup
could perhaps overcome this problem

What do you think?

Regards
JothiS

 

“Who wants to abandon defragmentation?”
I did – years ago.

“Perhaps TI does not restore the sectors at their original place”
AFAIK – that’s true, it does not.

“Restoring a full backup and making an incremental backup therefrom …”
I can see no reason to ever do that. If you restore, I would think that you would definitely want to start with a new FULL backup.

 

@TheWeaz

Just consider the following situation: Somebody uses the folder compression tool of WinXP ("compress content to save disk space"). Used disk space will look like a comb, thereafter. Without defragmentation you will notice a considerable loss of speed. (If you manage computers of others, you will see such things.)

Made a mistake during an installation and wanted to return to the last saved point (=my full backup)
After some mods I needed a new backup, but I still need the original one for other computers, too!
A small incremental would be the best solution.

 

Here are my stats, approximate sizes:

Full backup: 14.3 gb (saving 23gb on 2 drives.)
Non defrag increment: 5-6 gb
Defrag before incremental: 1.4-2.8 gb usually about 1.4-1.8 at 2% fragmented.

 

non defrag sould be .5-.6 gb

 

IMNSOHO, the best defrag program is still Perfect Disk, there's a $20 rebate if purchased from amazon by 30 April 2006.

Proper defragmentation results in visible performance improvements.

 

It makes no sense to not defrag periodically, especially with a proper defrag program.

 

Defrag or not, the size of a TI backup file should not be affected, if all TI is doing is copying sectors.

 

But the size of a TI incremental backup file will be affected by defrag.

 

Yes, I was referring to FULL backup.
I should have been explicit, shame on me!

 

Just clarifying since you had responded to the post by beckygb :
"non defrag sould be .5-.6 gb"
which was correcting a typo in a previous post about the size of the non defrag incremental.

 

Apropos data consolidation

I made a small test and I can't believe the results.
(Hope, I did not make a mistake!)

1. Full image of my test partition : 1.427 GB
2. Restore this image
3. Make an incremental backup of the same partition: 1.423 GB

The incremental is of the same size as the full image.
No defragmentation between the steps; just saving and restoring.

I think, the sequence used in the test is not unusal. Only some data changes
between the three steps are missing for a common scenario.
Does TI really work on sector level?
Is it possible to restore the partition on a sector basis?
( I am quite new to TI)

 

That's to be expected as TI does not restore the sectors to the same locations.

All you ended up doing was moving the files to different sectors and reducing the size of files such as the pagefile.

TI has two modes: drive mode and "files and folders" mode.
The former just copies sectors, but does NOT restore nack to the same sectors.

The latter works thru the file system and the location of restored files is determined by the file system.

TI does not do a pure sector image backup.

 

Howard, thank you for the information

 

Maybe, back in the day of inefficient file systems and slow hard drives, regular defragging had its place. But today, I’d need something more than “it seems faster” to believe it’s necessary. I've yet to be shown or to experience, any hard proof.

 

I have been using/admin Windows machines forever and, in GENERAL, I would AGREE with what you are saying. Todays hard drives are plenty fast to minimize the effect of fragmentation in the hard drive for regular use and regular users.

Once you start getting into heavier stuff, the situation changes a bit:

If you are manipulating LARGE files (bigger than say 700 MB)
If you are using memory intensive programs that would make you swap a lot as there is a MEASURED difference in the time windows swaps to a fragmented OR defragmented swap file.
If you use hybernation, not a drastic difference here but it does make a difference of a few seconds depending on your system.

In my case, I use PerfectDisk maybe twice a month to online-defrag C: and once a month an offline-defrag so it gets the swap and hybernation file.

I was having trouble upon reboot with my system where after login, some startup programs would take too long or just freeze and others would never start, very weird.

I found out that I had not defrag the C: drive since January and after defragmenting, everything is alot smoother upon reboot and login.

Guess it was not 'really' a fragmentation problem 'per-se', but the extra labor of the HD and extra time involved somehow created a 'funky' condition when login in after reboot.

Hard to believe uh?

 

THerer are a number of papers, from various sources, that clearly demonstrate the advantages of defragging. IE.g., 've previousl ypointed out that such papers are available at the Perfect disk, O & O Defrag and Diskeeper web sites.

And there are tools that can be used to demonstrate these advantages.

 

And the advantages of drinking milk can be found on the American Dairy Producers web site …

To each his own ...

 

The analogy is not valid.
THe results are easily reproducible.

I'm unsubscribing from this thread.
Good bye.

 

Bye.
I'm taking my toys and going home too.

 

I'm strictly in the "defrag whenever the mood might rarely strike me". I do not see any obvious performance differences at all. If I was running a server with a lot of users I might not have the same opinion.

You have to be very careful looking at numbers and extrapolating them to the real world regarding whether or not users actually notice any change at all. I'm quite sure the person who did the defragging feels he/she notices it .

Swapping a lot of data around on the HD is also another source of potential errors albeit a small one.

As TheWeaz said, to each his own; defrag all you want to but I'm sure not bothering.