From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from localhost (dhcp-100-19-150.bos.redhat.com [10.16.19.150]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p1FH4kdB026151 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Tue, 15 Feb 2011 12:04:46 -0500 Date: Tue, 15 Feb 2011 12:04:45 -0500 From: Mike Snitzer Message-ID: <20110215170445.GA20233@redhat.com> References: <20110214103112.4fb76864@bettercgi.com> <20110214181448.GC5825@agk-dp.fab.redhat.com> <20110215134115.GA19353@redhat.com> MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: Subject: Re: [linux-lvm] lvcreate and lvremove --quiet option is not quiet Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="iso-8859-1" To: LVM general discussion and development On Tue, Feb 15 2011 at 11:07am -0500, Jeff wrote: > On Tue, Feb 15, 2011 at 7:41 AM, Mike Snitzer wrote: > > On Tue, Feb 15 2011 at =EF=BF=BD8:02am -0500, > > Jeff wrote: > > > >> On Mon, Feb 14, 2011 at 12:14 PM, Alasdair G Kergon w= rote: > >> > The simple problem is that the code today does not distinguish betwe= en > >> > essential output (to stdout) and incidental output (to stdout). > >> > > >> > If I run 'pvs' I expect a list of PVs. > >> > If I run 'pvs --quiet' do I still expect to see that list? > >> > > >> > Today, there is no distinction: pvs output and the message you're wa= nting > >> > to suppress are the same category of message. > >> > >> Yes, there should be a difference between "do-something" commands and > >> "tell-me-something" commands. I hope there aren't too many cases where > >> that's a gray area. > > > > Ignoring the fact that we have a --quiet option for a moment, why is > > the additional output of the command(s) so problematic? >=20 > In short, the --quiet option isn't quiet. >=20 > In the case of lvcreate and lvremove it prints purely informational > confirmation messages to stdout. I find this somewhat inconsistent > with other linux commands that offer a --quiet option (rsync for > example). >=20 > It's not so much problematic as it is an issue of good design and > documentation. It's easy enough for me to send stdout to /dev/null in > my scripts, but that does run the risk of missing important > information in the case of unexpected results. What if the program > isn't so precise about sending error messages to stderr? well lvm _should_ send all errors to stderr. > As already stated, for commands such as lvcreate and lvremove where > the user is requesting the lvm system to "do something" and not "tell > me something" I think the --quiet option should actually make the > program be quiet, which it does not in the current implementation. Noted, definitely an lvm short-coming. > I am not a hard-core c developer and it's not likely that I would be > able to find the time to contribute trustworthy patches. If the > lvm-powers-that-be wish to ignore me, I can live with that. I simply > saw a potential improvement and chose to share my thoughts. Not ignoring you at all. This should get cleaned up. I was just pointing out that --quiet not actually being quiet isn't a showstopper at the moment -- so such a janitorial audit can be deferred. Thanks for the report, Mike