defrag

**blackcloud49** · November 7th, 2009

Does ubuntu come with its own defrag tool and if so where can I find it?

**wojox** · November 7th, 2009

Ah, no. Read up on Ext4.

**kyuubi777** · November 7th, 2009

forget all you learned on micro wincrap technologies... you shan't be needing them bits of info where your going

**MrDan** · November 7th, 2009

Originally Posted by kyuubi777

forget all you learned on micro wincrap technologies... you shan't be needing them bits of info where your going

I like that! It'd be a good bumpersticker...

**yo2boy** · November 7th, 2009

There's no need to defrag on an ext* system...

**ivanvajar** · November 7th, 2009

No fragmentation on ext* - no defragmentation.

**blackcloud49** · November 7th, 2009

Thanks

**calc** · December 8th, 2009

There is certainly fragmentation on Linux, and ext3 partitions can get extremely badly fragmented especially if you use transmission much, I know from personal experience. I have had numerous issues with downloadeds, eg Ubuntu 9.10, that are so fragmented I have to make a copy of them first to partially defrag them before I could burn them to disk, they couldn't even manage 48x cd speed (~ 7MB/s) on a drive that can do ~ 120MB/s sequential. Ext4 with prealloc is supposed to help somewhat with this issue, though I am sure it is far from perfect which is why tytso is also working on a defrag tool specifically for ext4. XFS also has a defrag tool, I'm not sure how well it works though, when I used it (8+ years ago) it ate my data.

I think the reason that the lie that Linux doesn't need to be defragged has been kept alive is due to the fact that until now only XFS has ever even had a defrag program (at least to my knowledge). This has been claimed since at least shortly after Linux was created probably because it was very hard if not impossible to write a defrag program for the older filesystems and people did not want there to be a clear public deficiency in Linux.

**calc** · December 8th, 2009

You can find out how fragmented a particular file is by running filefrag (filename). Also if you are using ext4 and manage to get it fragmented, I think you can resolve this simplying by doing a cp/rm which, at least to my knowledge, should use prealloc on ex4.