What`s the difference from chkdsk /f /r?

[necros2k7]

subj

[greatquux]

I think chkdsk /r only attempts to read sectors, even empty ones, without attempting to write anything. There are definitely cases where you need to try to write something and then read it back. Both SSDs and RAID arrays can re-allocate logical blocks from spare physical blocks only when they are overwritten, as they are not "sure" of the data in that logical block in the first place. So by using this program we can cause that re-allocation to happen.