Defragmentation

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Lots of stuff in another thread about file systems.

I mentioned defragmentation.  There seems to be a lack of understanding about  
what it is.  Has zilch to do with the TOC.

----
In the maintenance of file systems, defragmentation is a process that reduces  
the amount of fragmentation. It does this by physically organizing the contents  
of the mass storage device used to store files into the smallest number of  
contiguous regions (fragments). It also attempts to create larger regions of  
free space using compaction to impede the return of fragmentation. Some  
defragmentation utilities try to keep smaller files within a single directory  
together, as they are often accessed in sequence.

Defragmentation is advantageous and relevant to file systems on  
electromechanical disk drives. The movement of the hard drive's read/write heads  
over different areas of the disk when accessing fragmented files is slower,  
compared to accessing the entire contents of a non-fragmented file sequentially  
without moving the read/write heads to seek other fragments.
----
https://en.wikipedia.org/wiki/Defragmentation

Way back in the stone-age things like this were important when you were  
concerned about seek time and how it impacted performance.

Re: Defragmentation
On 21/04/17 23:39, Sidney_Kotic wrote:
Quoted text here. Click to load it

And is one of the reasons that Linux uses by and large file systems  
designed with all this in mind that don't actually fragment files. And  
massive file caching too, so that memory that isn't needed for anything  
else is acting as a fast random access copy of bits of the disk that you  
have used recently.


Of course these days with SSDS who gives a ****. The relationship  
between a requested track/sector isn't anything like constant as wear  
levelling algorithms rearrange the SSD on a routine basis anyway.

And there is no seek time.

--  
If you tell a lie big enough and keep repeating it, people will  
eventually come to believe it. The lie can be maintained only for such  
We've slightly trimmed the long signature. Click to see the full one.
Re: Defragmentation
On Fri, 21 Apr 2017 23:46:27 +0100, The Natural Philosopher

Quoted text here. Click to load it

I love the "blah blah blah" in reference #4 in the Wiki cited. Very
academic.
--  

Graham.
%Profound_observation%

Site Timeline