use newfs -m %free command to preset the percentage of free space

[pissallio]

We can use "newfs -m %free" to specify the amount of space on the slice that is reserved or held back from regular users.
What's the use of these reserved space on the slice ?

 

[mattaw]

Several reasons:

Firstly fragmentation:
This free space gaurantees enough spare room to prevent significant fragmentation of files as they are added to the drive. Note this effect happens even though users cannot actually write above the percentage as there is more contiguous areas available.

Secondly, root can write to that space:
This allows logs to continue to function and root to have room to move and sort things out after you fill it up.

Matthew

Family motto: Curvus, non infractus.
The Universe: God's novelty screensaver?

 

[pissallio]

Hi Matthew
In your reply:
Secondly, root can write to that space:
This allows logs to continue to function and root to have room to move and sort things out after you fill it up.

You mean that if a file system is mounted with the "logging" option, the log file of the file system will take up the reserved space on the disk.
Am i right?