Date: Thu, 21 Jan 2016 06:35:02 -0800 From: Cy Schubert <Cy.Schubert@komquats.com> To: Slawa Olhovchenkov <slw@zxy.spb.ru> Cc: Andriy Gapon <avg@FreeBSD.org>, "svn-src-head@freebsd.org" <svn-src-head@FreeBSD.org>, "svn-src-all@freebsd.org" <svn-src-all@FreeBSD.org>, "src-committers@freebsd.org" <src-committers@FreeBSD.org>, Alan Somers <asomers@FreeBSD.org> Subject: Re: svn commit: r294329 - in head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys Message-ID: <201601211435.u0LEZ2Ns046079@slippy.cwsent.com> In-Reply-To: Message from Slawa Olhovchenkov <slw@zxy.spb.ru> of "Thu, 21 Jan 2016 14:38:14 %2B0300." <20160121113813.GG37895@zxy.spb.ru>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <20160121113813.GG37895@zxy.spb.ru>, Slawa Olhovchenkov writes: > On Thu, Jan 21, 2016 at 01:34:57AM +0200, Andriy Gapon wrote: > > > On 20/01/2016 22:03, Alan Somers wrote: > > > On Wed, Jan 20, 2016 at 2:20 AM, Andriy Gapon <avg@freebsd.org> wrote: > > >> On 19/01/2016 19:20, Alan Somers wrote: > > >>> The thing is, it never really worked in the first place. Panics and > > >>> deadlocks are so frequent that I don't think the feature was usable > > >>> for anybody. > > >> > > >> The feature is perfectly usable for me. I have never run into the probl > ems that > > >> you describe. Why not fix the real bugs that you've run into? > > > > > > Spectra Logic and iXSystems both experienced many problems with this. > > > The worst is a deadlock that can be triggered simply by pulling a > > > drive from a redundant pool when there exists a zvol anywhere in the > > > system (see https://reviews.freebsd.org/D4998 for a quick way to > > > reproduce). Fixing it correctly would likely require far more time > > > than I have available. I just want the bugs to go away. See that > > > same code review for a change to make the feature optional. > > > > I think that we all want all the bugs to go way. One way to remove bugs is > to > > remove (disable) code that contains bugs. That way the perfect bug-free > > software is clearly achievable :-) Unfortunately, that technique is not al > ways > > welcomed. > > > > P.S. > > I think that the real problem here is that a method of a geom must never dr > op > > topology_lock. In other words, the GEOM management code (like g_xxx() stuf > f in > > geom_subr.c) expects that a topology can not change underneath it. But > > zvol_geom_access() clearly breaks that contract. > > May be same cause problem with swap on zvol (don't test on latest > -stable)? Not related but should be disabled by default through sysctl is vdev on USB. OK for a laptop but not a server. 100% hang on shutdown/reboot. -- Cheers, Cy Schubert <Cy.Schubert@komquats.com> or <Cy.Schubert@cschubert.com> FreeBSD UNIX: <cy@FreeBSD.org> Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201601211435.u0LEZ2Ns046079>