Defragmenting drive?

[Viro]

I've been running Knoppix off my hard disk for nearly a month now. I'm wondering if I need to run a defragmenter on my hard disk (used to do this every month on Windows). I've found a tool that defragments ext2 drives, but my drive is formatted using ReiserFS.

I've done some web searching and come up with nothing really useful. Could anyone help?

[fingers99]

No, essentially you only need to do it in extremely rare circumstances. As a rule, you're far better off leaving Linux filesystems to take care of themselves: if any action is needed, the system will post a warning.

[Coume]

But when you have a warning, what command to you have to use to defragment?

Is there any software that are available in the KDE evironment? Or are they all text based?

Ludo

[Viro]

After reading more about ReiserFS from http://www.namesys.com, I think it doesn't need to be defragmented. The following quote from the article

ReiserFS is based on fast balanced trees. Balanced trees are more robust in their performance, and are a more sophisticated algorithmic foundation for a filesystem. When we started our project, there was a consensus in the industry that balanced trees were too slow for filesystem usage patterns. We proved that if you just do them right they are better. We have fewer worst case performance scenarios than other filesystems and generally better overall performance. If you put 100,000 files in one directory, we think its fine; many other filesystems try to tell you that you are wrong to want to do it.

The way I understand it, because it uses balanced trees, file fragmentation should rarely occur. Fragmentation is where parts of a file are scattered over the harddisk. IIRC, an NTFS/FAT drive needs to be defragmented because it uses a table to store the locations of file fragments. Because of the way balanced trees work (look up a good book on programming algorithms on this), it reorders (i.e. reposition) file fragments each time a new file is added, preventing/minimizing fragmentation. That's why it mentions that people thought that balanced trees in filesystems would be slow.

In short, you won't need to defragment. Cool.

[Coume]

The way I understand it, because it uses balanced trees, file fragmentation should rarely occur. Fragmentation is where parts of a file are scattered over the harddisk. IIRC, an NTFS/FAT drive needs to be defragmented because it uses a table to store the locations of file fragments. Because of the way balanced trees work (look up a good book on programming algorithms on this), it reorders (i.e. reposition) file fragments each time a new file is added, preventing/minimizing fragmentation. That's why it mentions that people thought that balanced trees in filesystems would be slow.

In short, you won't need to defragment. Cool.

GOSH, I was not thinking such thing was possible
I still have lots of things to discover about computers! eheh

But that's good if we do not need to defragment!

Ludo