4/30/14 7:02 PM

I'm trying to figure out what is going on with my (relatively) new external hard drive. I use it for my weekly backup. It's a 1,000 Gb drive and Properties says it's got 833 Gb on it. But when I look at the actual files and folders they total to 220 Gb. There's no file or folder with the date of my latest backup. I have the view properties set to show hidden files.

Am I correct in assuming that the Windows backup doesn't show up when I look at the drive? And how might I free up some space on the drive?

4/30/14 7:10 PM

What is the sector size on the drive?

4/30/14 7:25 PM

Don't know the sector size - the drive is not partitioned to my knowledge. It was sold as a 1,000 Gb drive and Properties shows 895 Gb used and 105 Gb free. Tell me how to determine sector size.

4/30/14 7:34 PM

The point is really if you have a 1kGB drive with 4096k sectors, every file that is one byte over 4096 will use the rest of the byte in that last sector.

So the backup file being a contiguous single file is important so the slack space does not eat up too much capacity.

If the drive has 512k sectors, less slack space wasted, but the FAT [File Allocation Table] or what ever it might be referred to these days will be 8 time as large potentially. Another sort of slack space use.

Now if it is NTFS formatted, I admit being rusty in the technologies and the benefits, of each.. By Windows what version is the default NTFS, or maybe something beyond my old experience, I dunno...

4/30/14 7:40 PM

So how does one determine how many sectors are on this drive?

4/30/14 8:17 PM

Dunno

5/2/14 10:39 AM

This url should explain things nicely for you:
http://www.glyphtech.com/support/diskcapacity.php

5/2/14 7:22 PM

quote:

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This url should explain things nicely for you:

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5/3/14 6:37 AM

A utility like http://windirstat.info/ should reveal how your disk space is being used.
Try googling: "windows backup" "missing disk space"

5/3/14 7:47 AM

The native Backup & Restore utility is not very telling of how much space is used, IIRC. Windows purposefully hides the backup files, too. You know all this already.

However, if you right click in Windows Explorer the external drive's properties popup menu selection, then selected the Previous Versions tab, then select a backup from the list, and then select Open, it will then give you an idea how much space is used by the respective backup.

With a weekly backup, I reckon that will build up the hidden archive quite fast. That is when you consider Microsoft constantly releases software updates.

What I recommend you do is, if your computer is running fine, is to periodically remove the backups. It all depends on your comfort level. Additionally, you can have the backups space "compressed" to save disk space.

I'm not quite as cautious/conservative as you. I don't do frequent Windows backups. Periodically I will will remove any Windows backups to conserve disk space - especially on my 24GB SSD netbook.

The reason being is that I can always reinstall Windows and have the updates reinstall (many!). While this will require much more time to do than restoring from a recent backup, I consider this risk of needing to reinstall/restore Windows *very* low.

This may not be an option for some. Many new computers do not include a Windows OS cd/dvd. With that, the only option is to rely on the backup & restore utility. Keeping a full history of the backups, especially on a weekly basis should not be necessary.

5/3/14 7:09 PM

So with the Manage Space link on the backup and restore page, you get a summary of disk space usage. Backup is 270 Gb, System image is 398 Gb, and some other files I have stored on the disk total 139 Gb. I take it that system image is a relatively fixed number or is it a collection of previous images? There are dozens of previous versions on the HD but I don't see a way to delete them.

I suppose the quickest way to reduce the backup volume is to do a fresh backup and delete the previous backups.

5/4/14 12:13 AM

All I ever backup are my data files - documents, pictures, videos, music, email, etc, using either robocopy for windows machines or rsync for Linux machines. I alternate week and week about between two external disks in drive enclosures, and store the external disk I'm not using in our garden shed...