Can "minfree" be set to 0% for UFS?

[aragats]

According to newfs() and tunefs() the option -m (the percentage of space held back from normal users): "Settings of 5% and less force space optimization to always be used which will greatly increase the overhead for file writes".

Can it be set to 0% without losing performance — since there is nothing to optimize? E.g. if I have a partition used as a storage for not-so-important stuff, and I don't care if it doesn't have reserved space.

 

[mer]

I'm not sure if there is a relation between this value and what root user can do, but the part you quoted says "...greatly increase the overhead for file writes". Couple that with you saying "...a partition used as storage..." the implication is it may take longer to do the writes to storage which is a potential performance hit..

I think on UFS that specific value only comes into play as a file system fills up, so if the filesystem is say less than 70% utilization there may be no measurable difference. As the filesystem fills up, things may/will change.