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Why does defragmantation happen in six passes, and why does it take hours?

Anonymous
2014-10-21T18:54:34+00:00

For a few weeks now I've had some issues with my laptop slowing down and my hard drive mysteriously filling up with extra gigabytes even though I'm not downloading anything. Yesterday I cleaned up a few files, and as a result the computer surprisingly said that 6 GB more had been added to the hard drive! No idea how that happened.

My OS is Windows 8.1 (64-bit), so it has a scheduled defragmentation process which happens every week. Despite this I decided to perform a manual defragmentation, since I had never done one in Win 8.1. I found the "Optimize Drives" window and went ahead with optimizing the C hard disk drive. When I started the capacity of the drive was 421 GB, and 119 GB (28 %) of that was used space.

Here is my issue:

It went unbelievably slowly! It started out with stage "Pass 1" (something I had not encountered in previous Windows versions). First the "relocated" phase took almost four hours. For the whole time I thought that would be the only phase, since it took so long. However, then the "defragmented" phase started, which luckily that didn't take long, and after that the "consolidated" started which took about 30 minutes. After this I thought the process must be done, but then it started again with the "Pass 2" stage! This whole "Pass 2" stage with relocate, defragment and consolidate took another two hours. After this came stages "Pass 3", "Pass 4" and "Pass 5". During this "Pass 5" phase I had to move somewhere else and put my laptop to sleep, thinking that the defragmentation process would continue when I woke up the computer again. This however did not happen. The computer didn't wake up from sleep mode and I had to restart it.

Questions:

  • Is the defragmentation process supposed to take hours? In my last computer with Windows Vista it took 5-10 minutes and then it was done. If it takes this long, what does it say about the state of the hard disk drive, if anything?
  • I found this site which claims that Windows 8 does the defragmentation in two passes. Just minutes ago I finished doing the defragmentation process again on my laptop, since the last time the laptop did not wake up from its sleep mode and I had to restart it. The process reached "Pass 6" before it finished. Why so many passes?
  • I earlier said that 119 of 421 GB was used up. Now after defrag the number is down to 114 GB, which is a good thing. This is what I mean:

But when I look at the folders (both visible and hidden) on drive C (below), and calculate their combined size, they total only 104 GB. So the picture above says 114 GB, but the individual folders total only 104 GB, meaning 10 GB less. Why is that? What are the 10 GB that are not included in the folders? (Before defrag the numbers were 100 GB in total in folders, and 119 GB on hard drive, which means 19 GB were unaccounted for.)

My laptop is currently 10 months old. I use it every day for hours, but I'm by no means technically skilled. Therefore I don't make any major changes in settings or download any special programs. I only use it for basic office work and listening to music. The security software is Trend Micro Titanium Maximum Security, and it's up-to-date, so I should have no major bugs on the laptop. The brand is Lenovo, and the model is G500. CPU: Intel Core i5-3230M, 2.60GHz.

There is no rush with this problem, I'm just genuinely interested in understanding this.

Thanks in advance for any help!

Windows for home | Previous Windows versions | Performance and system failures

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Anonymous
2014-10-22T12:43:37+00:00

Hi ,

Thanks for posting in Microsoft communities.

As per your description provided you have mentioned that you have issues  with your laptop slowing down and your hard drive mysteriously filling up with extra gigabytes even though you’re not downloading anything. Folders like 'WinSxS' and 'users', go on swollen by themselves as time pass on. But one fails to know how to reduce reduce this phenomenon. The windows user has no choice to  delete some of these. When the swelling process reaches a certain limit, all on a sudden the whole C drive gets a red color on explorer, and the system stalls. This is in spite of the limited number of applications.

I would like to ask you few questions so that I can have a clear picture of the issue.

a. Are you getting any specific error while you use your computer?

b. Are there are antivirus software installed in your computer?

c. How much free disk space does the partition have and how large is the partition?

d. Did you run Disk Cleanup or Ccleaner before you started?

Whenever you install something on the Operating System a restore point automatically gets created. So, the hard disk space has decreased. But if you want, you can fix how much space you want to allocate for system restore.

Method 1 - As you have mentioned that your hard drive mysteriously filling up with extra gigabytes even though you’re not downloading anything.

Follow these steps given below:

a. Press Windows key + Pause/break key to open system properties.

b. Now select System Protection and select the drive in which you have installed the Operating

sys.

c. Select Customize and allocate the amount of drive space you want to allocate.

d. Click Ok.

I would like to refer a link regarding about how to improve performance by optimizing your drive, please click on the provided link below:

http://windows.microsoft.com/en-in/windows-8/improve-performance-optimizing-hard-drive

Due to the required space and filling the computer might act slow or may be other reason so in that case we can Check a drive for errors,

http://windows.microsoft.com/en-in/windows7/check-a-drive-for-errors

As per your questions:

How Long Should a Defrag Take?

Obviously, the time it takes for a disk to defragment will be different from computer to

computer and disk to disk. It depends on disk size, percent of disk use and amount of fragmentation. It depends on how big the disk is, how bad it is, how full it is, and what you have running at the same time.There is a possibility it might take total of about 10 hours and 12 passes. Also, after each pass, the computer has to "recollect" data which can take time. Fragmentation only

affects the speed that the particular file can be read/written at, as almost all of those files seem to be ones that don't actually matter (mainly installation files).

Let us know about the status of the issue. We would be happy to help you

further.

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  1. Anonymous
    2015-11-21T18:02:36+00:00

    It's almost similar to moving a file. But just imagine what happens when you move a file from one folder to another. In case if it is interrupted. You will have some loss of bytes. In defragmentation, you are spreading up fragmented files so that your computer finds easier for searching and processing a file instead of digging in a particular part. The moving of blocks need to be done carefully to reduce any file loss and corruption. In pass 1 blocks will be analyzed, defragmented and consolidated. Any block missed will be taken care by repeating the same above procedure. i.e, pass 2. And the process continues till the defragmenter assures that all blocks are moved safely. Therefore more the pass, more the accuracy and safety.

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  2. Anonymous
    2017-03-12T19:20:27+00:00

    It's almost similar to moving a file. But just imagine what happens when you move a file from one folder to another. In case if it is interrupted. You will have some loss of bytes.

    Balaji, you had better not EVER lose even ONE data byte during normal operations!!!

    Yes, there will be a number of them occupying various, seemingly-random (non-contiguous) memory locations i.e., "sprinkled" throughout each media - apart from the bulk of their files - but never "lost" or "forgotten" - during NORMAL operations.

    (This does not apply in cases of unexpected or forced terminations, etc.)

    Otherwise, there's file corruption, damaged hardware, and/or viruses to correct.  :-(

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  3. Anonymous
    2016-09-15T13:54:42+00:00

    Thanks, Balaji Chandramouli, for this information on the methodology of drive optimization. I have unsuccessfully looked for such an explanation for quite some time.

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