28% and 35% Fragmented Files a Concern?

[Smartazz]

Hello all, just ran Auslogics disk defrag and it says 28% fragmented on my 1TB drive and 35% on my 640GB drive. I've never seen these numbers get this high, but I didn't notice much of a performance hit since I guess I'm using my SSD most of the time and the two hard drives are mainly mass storage. Keep in mind the 640GB drive reports 35% fragmented after I defraged it, so I'm assuming there's not enough space to do a meaningful defrag? I also compressed the drives to save space, could this have caused a rise in the fragmentation rate? Before compression, both drives were very close to being full so I compressed them to save some space. Was this a bad idea?

 

[KingFatty]

Does that defrag program understand compressed drives? Maybe it's confused about the compression, and maybe the compression itself does some trick optimization that causes the issue but benefits the performance of the compressed drive? Just speculating...

 

[greenhawk]

never heard of that software. sure they are not wanting you to buy the software?

As to the files, if not enough space, defrag will not work correctly.

Under windows IIRC it does something with files larger than 64MB and does not defrag them even if fragmented.

 

[Cerb]

% fragmented can be given in ways to make things seem worse than they are. If fragments average in the tens of MB each, performance differences will only show up in file copy benchmarks. If you have NCQ, the difference will be less. Only small often-accessed files with many fragments are a problem worth worrying about. % fragmented does not speak to the nature of the fragmented files.

Compression isn't your problem. The numbers are high because you don't have the drive space for Windows to prevent high fragmentation as files are stored and edited. This happens with any FS, NTFS is just already highly susceptible to light fragmentation. If there isn't enough room to save a file in one contiguous chunk, it goes in smaller chunks in between other files.

Windows has gotten better over the years, as have drives. Part of Windows getting better has been adding good file caching as of Vista. Unless there are certain small files that you access a bunch that have many tiny fragments, it's largely wasted worrying. Smart people have spent a lot of time on this problem so that you shouldn't have to care about it .

 

[Nothinman]

All defrag tools do their damnedest to show you a scary number and convince you that their software is worth your money. It's a statistic like any other and can be manipulated to be just as good or bad as people want.

If you're not noticing any performance issues, then don't worry about it.

 

[lsv]

Why are you compressing your drives? It's 2012.

 

[corkyg]

As a general rule, it is prudent to have 25% of a HDD's capacity as free space. This not a requirement, but simply a prudent practice that helps us keep drives healthy. Compression of data can slow down overall performance. What is compressed has to be decompressed for normal access.

 

[KingFatty]

But I believe if you compress a drive, the drive could be perceiving itself as storing a really big file. Like one big zip file? Then, that one big zip file could be completely defragged, no fragmentation at all, and yet the defrag program would be confused and think your files inside the zip are fragmented, when they are actually fine because there is some behind-the-scenes magic done by the compression/decompression on-the-fly that confuses the defrag program unless it's specifically designed to understand the structure inside the compressed drive? If someone with more knowledge on how compression interacts with defrag could chime in...

 

[Nothinman]

As a general rule, it is prudent to have 25% of a HDD's capacity as free space. This not a requirement, but simply a prudent practice that helps us keep drives healthy. Compression of data can slow down overall performance. What is compressed has to be decompressed for normal access.

So you would try to keep at least 500G free on a 2TB volume?

But I believe if you compress a drive, the drive could be perceiving itself as storing a really big file. Like one big zip file? Then, that one big zip file could be completely defragged, no fragmentation at all, and yet the defrag program would be confused and think your files inside the zip are fragmented, when they are actually fine because there is some behind-the-scenes magic done by the compression/decompression on-the-fly that confuses the defrag program unless it's specifically designed to understand the structure inside the compressed drive? If someone with more knowledge on how compression interacts with defrag could chime in...

The drive doesn't perceive anything, it doesn't understand partition tables, file systems, etc.

And the compressed volume in one big file thing hasn't been true since Win 3.11/Win9x. NTFS does compression on a per-file basis on the block level as part of the basic filesystem features.

 

[billyb0b]

never heard of that software. sure they are not wanting you to buy the software?

As to the files, if not enough space, defrag will not work correctly.

Under windows IIRC it does something with files larger than 64MB and does not defrag them even if fragmented.

Auslogics has been around for a while and makes a great defrag program. I've been using it on mechanical drives for some time.

 

[Smartazz]

Why are you compressing your drives? It's 2012.

I freed up over 70GB on my 640GB drive by compressing so I find it as a valuable method of saving space, especially since this data is rarely accessed, but I do need these files occasionally.

 

[lsv]

I freed up over 70GB on my 640GB drive by compressing so I find it as a valuable method of saving space, especially since this data is rarely accessed, but I do need these files occasionally.

Then why care about defrag values?