fsck parallel check

[Wojciech Puchar]

> Quoting the manual:
>
>     In other words: In preen mode all pass 1 partitions are checked
>     sequentially.  Next all pass 2 partitions are checked in parallel, one
>     process per disk drive.  Next all pass 3 partitions are checked in
>     parallel, one process per disk drive.  etc.

Yes i've read this manual.


"Next all pass 2 partitions are checked in parallel, one
process per disk drive."


so having 5 partitions on one SSD - it will be checked sequentially.

> Also note that "one process per disk" refers to old traditional partition numbering
> like da0s1a, da0s1d, da0s1e that fsck recognises as belonging to same "disk"
> but not to newer label-based mount like /dev/ufs/root, /dev/ufs/var or /dev/mirror/m0s1a etc.
> so it runs it all in parallel unless you deny it using different pass numbers.
>
i use /dev/gpt/gptlabel naming. so it will check in parallel.