heavily fragmented file system.. How to defrag it on-line??

Guolin Cheng guolin at alexa.com
Thu Mar 4 02:27:51 UTC 2004

Hi, Ted,

 Thanks for your response

>>  I got machines running continuously for long time, but then the underlying ext3 file systems becomes quite heavily  fragmented (94% non-contiguous).

> Note that non-contiguous does not necessarily mean fragmented.  Files
> that are larger than a block group will be non-contiguous by
> definition.  On the other hand if you have more than one file
> simultaneously being written to in a directory, then yes the files
> will certainly get fragmented.

Yeah, the reading|writing speed is about 10 times slower. the original speed is about 20-40MB/s, while now it is about only 1-5MB/s. We normally write the disk to >90% full, then delete lots of files, write new files again to about >90%, then delete again.

>There rae no on-line defrag tools right now, sorry.

So I have to use gtar to save data, then re-create new file system, at last use gtar to copy data back? That will take long time and have to stop existing processes on the machines. Definitely that is the last solution I will consider.

Are there any plans to develop a tool to defrag ext3 file systems on-line?


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