fsck and non-contaigous - meaning
 

Sometimes when I do fsck -yf, I get output: 9.1% non-contaigous.
Wondering what does this mean?

Thanks.

It's telling you that 9.1% of the filesystem's contents are fragmented to some degree.

If it bothers you, use LQ's search feature to find other threads talking about fragmentation. All filesystems suffer from some fragmentation. Some of them pro-actively try to minimize it. Some do nothing. The threads you find will point out tools and/or rationales for or against defragmenting Linux filesystems.

I think you mean "non-contiguous"?

Assuming you do, non-contiguous data is basically the same as fragmented data on a Microsoft filesystem.