Re: xfs_scrub: call for testing

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Mon, Feb 05, 2018 at 06:08:07PM +0100, Emmanuel Florac wrote:
> Le Mon, 5 Feb 2018 09:49:41 -0600
> Eric Sandeen <sandeen@sandeen.net> écrivait:
> 
> > > 
> > > Wouldn't it be better to remove the parts about repairing the
> > > filesystem in the documentation? The man page states that it *can't*
> > > repair the filesystem, but nonetheless explains under which
> > > circumstances it *won't* be able to repair (in some theoretical
> > > future version with repair capabilities, I suppose). Ditto with the
> > > -n and -y option, I suppose they're both basically noop at the
> > > moment? That's quite unclear what it actually does.  
> > 
> > I'll take another look at the manpage.  The userspace tool today /can/
> > do some degree of optimization or repair if the kernel supports it,
> > so I was reluctant to suggest removing all such language.
> > 
> > So, "-n" is not a no-op, it's a check-only ("scrub") pass vs. the
> > default no-argument action of "optimizing," or the extra -y action
> > which would repair. If that's not all clear, I'd appreciate
> > suggestions to clean it up.
> > 
> 
> Now I'm wondering: is the default option of "optimizing" really
> useful? Wouldn't it be better to simply have a check-only (-n) version,
> and a full-fledged version when given no argument? 
> Or maybe do a simple optimisation, optionally,  when given the '-y' (or
> some other flag) option? 
> 
> I say that after having a look at man pages from some comparable
> utilities, namely xfs_repair, btrfs_scrub and "zpool scrub", who all
> default to "full operation" without options.

I don't care /that/ much about what 'zpool scrub' does, but I do see
your point that from the admin's perspective either we fix everything or
we don't, so there's no need for a -y and we can do what repair does (-n
means dry run, lack of -n means fix it).

--D

> 
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