Disk defragmenter in Linux

[Mike McCarty]

Jim Cornette wrote:
> Mike McCarty wrote:
> 
>> Jim Cornette wrote:
>>
>>> John Summerfied wrote:
>>>
>>>> Jeff Vian wrote:
>>>>
>>>>>
>>>>> Exactly, and IIRC the filesystem knows that if it needs X amount of
>>>>> space for a file, then Y number of inodes are marked for use for that
>>>>> file at the beginning.  Thus space allocated is as contiguous as is
>>>>> efficient for read/write on the disk.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> If "the filesystem knows that if it needs X amount of space for a 
>>>> file," that implies there's a way of telling it that.
>>>>
>>>> How's that done? I don't recall any system call for *x (there is one 
>>>> for OS/2), and one could do it in JCL in IBM's OS in the 60s), but 
>>>> in the *x world I've never seen a way to do it.
>>>
>>>
>>>
>>>
>>>
>>> Since the discussions regarding fragmentation on ext3 filesystems was 
>>> pretty long running. I decided to try
>>> filefrag /usr/bin/* |sort |grep 'would be'
>>> and the output showed a lot of fragmentation. One of the files was up 
>>> to 45.
>>
>>
>>
>> On my system I did this...
>>
>> # filefrag /usr/bin/* | sort -k2 -nr | grep 'would be'
>>
>> Here're the first few entries...
>>
>> /usr/bin/emacs: 248 extents found, perfection would be 1 extent
>> /usr/bin/emacs-21.3: 248 extents found, perfection would be 1 extent
>> /usr/bin/kermit: 80 extents found, perfection would be 1 extent
>> /usr/bin/kbabel: 45 extents found, perfection would be 1 extent
>> /usr/bin/ddd: 45 extents found, perfection would be 1 extent
>> /usr/bin/gthumb: 41 extents found, perfection would be 1 extent
>> /usr/bin/gdbtui: 36 extents found, perfection would be 1 extent
>> /usr/bin/elinks: 30 extents found, perfection would be 1 extent
>> /usr/bin/iniomega: 22 extents found, perfection would be 1 extent
>> /usr/bin/kpersonalizer: 21 extents found, perfection would be 1 extent
>> /usr/bin/artsd: 21 extents found, perfection would be 1 extent
>> /usr/bin/artscat: 20 extents found, perfection would be 1 extent
>> /usr/bin/kiconedit: 19 extents found, perfection would be 1 extent
>> /usr/bin/glade-2: 19 extents found, perfection would be 1 extent
>> /usr/bin/karm: 18 extents found, perfection would be 1 extent
>> /usr/bin/dia: 18 extents found, perfection would be 1 extent
>> /usr/bin/designer3: 18 extents found, perfection would be 1 extent
>> /usr/bin/designer: 18 extents found, perfection would be 1 extent
>> /usr/bin/kppplogview: 16 extents found, perfection would be 1 extent
>> /usr/bin/kfontinst: 16 extents found, perfection would be 1 extent
>> /usr/bin/civclient-xaw: 15 extents found, perfection would be 1 extent
>> /usr/bin/cdrecord: 15 extents found, perfection would be 1 extent
>> /usr/bin/knewstickerstub: 14 extents found, perfection would be 1 ext
>>
>> Surely those who argue that ext3 does not get fragmented
>> during install don't think that 248 extents is "not
>> significant fragmentation".
>>
>> I assure you that I have done nothing on my system to try to
>> fragment emacs.
>>
>> Mike
> 
> 
> 
> The fragmentation for your emacs is unbelievably high. I did not find 
> anything yet fragmented in the hundreds, let alone several hundred 
> extents. Are you using LVM? My system is setup in traditional 
> partitions. LVM usage "seemed" slower in responsiveness, so I assumed it 
> was more in fragments

Why "unvelievably"? Do you mean that you do not believe what my
system says? Or that you do not believe my e-mail? Or that you
find that it stretches your imagination? Or what?

To answer your question, I use FC2.

Mike
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