Defrag?

spaceballs · 03-30-2005, 12:25 PM

For a while, I was a windows system administrator. Don't even start with me, it was terrible.

These systems must be defragged once (twice) a week, or they really start operating poorly.

I have been using linux on a few different systems for three-four years, and have not had any issues with this.

Why does linux not need to be defragmented? Or does it need to be, and how do I do it?

linmith · 03-30-2005, 12:32 PM

As far as I know you don't have to defragment linux, I think I remember reading that somewhere...but don't quote me on that

keefaz · 03-30-2005, 12:45 PM

The most of linux filesystems (if not all) have built-in defragment procedure.
So when you rm or cp a file, you actually do a defrag at the same time

xushi · 03-30-2005, 12:46 PM

That's true, but i've read that you could have slight fragmentation if you frequently fill up your hard drive...

keefaz · 03-30-2005, 12:49 PM

This is obvious as the filesystem has not enough room to do defrag block manipulation if the partition is full of data (I think it need like 5/10% of free space)

spaceballs · 03-30-2005, 01:10 PM

I guess my real question is why does windows fragment its hard drives, and why does linux not?

keefaz · 03-30-2005, 01:29 PM

look at:
http://www.linux-sxs.org/housekeeping/frag.html

They tell about ext2 but you can extand it to other filesystems

rshaw · 03-30-2005, 01:34 PM

Quote:

Originally posted by spaceballs
I guess my real question is why does windows fragment its hard drives, and why does linux not?

bad design, good design

carboncopy · 03-31-2005, 12:35 AM

Well, this is what I read somewhere. Can't remember.

You don't have to worry about fragmentation in NTFS (Windoze). And definately not in ext3, reiserfs, jfs, xfs, etc.

Why? Cause there won't be much performance hit caused by the fragmentation.

Ask me to produce the source? I can't. But, Amit Singh have an article on HFS+ fragmentation.

You can thrown him some question at his forum.

chbin · 03-31-2005, 01:17 AM

Quote:

Originally posted by carboncopy
Well, this is what I read somewhere. Can't remember.

You don't have to worry about fragmentation in NTFS (Windoze). And definately not in ext3, reiserfs, jfs, xfs, etc.

Why? Cause there won't be much performance hit caused by the fragmentation.

Are you sure about that NTFS thing. It seemed to get pretty fragemented when I used it. Also windows XP defragements when your computer is idle and moving files that you use a lot to the front of the drive. None the less it still got slower and slower as time went on, but this is typical of any microsoft product so it's hard to say if the filesystem was a contributing factor.

carboncopy · 03-31-2005, 01:19 AM

I am not sure

That is what I read somewhere. So, not verified. However, using diskeeper does help.

But, I don't have windoze on my own machine anymore.

linuxhippy · 03-31-2005, 09:36 AM

when Linux boots, the cfdisk script is run and every 30 days it cleans your harddrive-I would think this is a defrag procedure?

keefaz · 03-31-2005, 09:48 AM

No cfdisk is a partionning tool, maybe you tell about fsck instead ?
In this case, fsck is a tool that check and repair filesystems.

defrag is really done on the fly, when you save a file, copy, delete...
The filesystem try to do its best to put the data blocks in continguous disk spaces

linuxhippy · 03-31-2005, 10:19 AM

You're right-I'm not at a Linux box...I meant fsck.

masonm · 03-31-2005, 11:24 AM

The difference is in how the different file systems organize and access the files. Linux filesystems actually organize the files in a logical manner instead of just writing them willy-nilly wherever they will fit in. Windows filesystems are very crappy in that regard and have to be defragmented regularly in order to speed up access times because the files are written all over the place with no sort of logical organization to them.