Regarding Filesystems

Pedro F. Giffuni pfgshield-freebsd at
Sun Jul 27 10:39:45 PDT 2008

Hi Adam;

Adam Emanuel wrote:
Hello Sir,
I'll only answer the UFS question, I don't know hammer well enough but 
is somewhat like a logging fs so I don't think it can be compared at all 
to a journaling fs.

1- I know that UFS divides the disk into cylinder group, does this has
anything to do with disk's physical cylinders, let's say they are the
same thing ?
This is a common misconception: it used to be (in archaic disks) that
UFS would use the cilinder information to improve performance, however 
the results were so good that modern disks adopted the optimizations and 
now basically hide that information. In UFS2, and late UFS1, the 
"geometry" values are still used for organizational purposes but have no 
relation to the physical disks at all.



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