> Once power down occurs, the NetBSD server will check file system at next
> startup, it will take as long as 10 minutes.
> I have done a test on Linux (ext3), it take only 10 seconds to recover.
Periodically fsck-ing ext3 takes much more time. AFAIR when you didn't
run fsck for 28(?) reboots or after several hundrets of uptime
days... fsck_reiserfs3 is also slow (relatively).  Under Linux
fsck_jfs is really fast in all cases and is stable (for me?), I never
used XFS.

> So, I think ffs v1 is not suitable for my environment.

> Then, which file-system on NetBSD I should select?
> ffs v2? lfs? or others?
I'm not sure about ffs but I don't recomment you LFS for use in
production.  I have lots of problems with it even on my home machine
used primarily for development.

-- 
Best regards, Aleksey Cheusov.