From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: What is the state of blktap2? Date: Fri, 22 Jan 2010 10:43:28 -0800 Message-ID: <4B59F1D0.1080103@goop.org> References: <1264112865.20158.5.camel@moss-terrapins.epoch.ncsc.mil> <20100121223828.GD2861@reaktio.net> <1264113965.20158.8.camel@moss-terrapins.epoch.ncsc.mil> <20100121225552.GE2861@reaktio.net> <20100121225933.GF2861@reaktio.net> <1264115626.20158.15.camel@moss-terrapins.epoch.ncsc.mil> <20100122071419.GG2861@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20100122071419.GG2861@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: =?ISO-8859-1?Q?Pasi_K=E4rkk=E4inen?= Cc: "David P. Quigley" , xen-devel@lists.xensource.com, Ian Campbell , Daniel Stodden List-Id: xen-devel@lists.xenproject.org On 01/21/2010 11:14 PM, Pasi K=E4rkk=E4inen wrote: > On Thu, Jan 21, 2010 at 06:13:46PM -0500, David P. Quigley wrote: > =20 >> On Fri, 2010-01-22 at 00:59 +0200, Pasi K=E4rkk=E4inen wrote: >> =20 >>> On Fri, Jan 22, 2010 at 12:55:52AM +0200, Pasi K=E4rkk=E4inen wrote: >>> =20 >>>> On Thu, Jan 21, 2010 at 05:46:05PM -0500, David P. Quigley wrote: >>>> =20 >>>>> On Fri, 2010-01-22 at 00:38 +0200, Pasi K=E4rkk=E4inen wrote: >>>>> =20 >>>>>> On Thu, Jan 21, 2010 at 05:27:45PM -0500, David P. Quigley wrote: >>>>>> =20 >>>>>>> I'm currently working on moving storage services into their own d= omain >>>>>>> and I've been looking at blktap2. I've been trying to get an imag= e >>>>>>> mounted with blktap2 and for some odd reason and tapdisk2 keeps h= anging >>>>>>> instead of quitting at the end. I haven't removed any of the stor= age >>>>>>> startup code at this point so everything should be as it normally= is in >>>>>>> xen-unstable. Is this a known bug? Are there some requirements on >>>>>>> blktap2 that I'm possibly not meeting? Is there anything in parti= cular >>>>>>> that I should be looking at to try to debug the problem? >>>>>>> >>>>>>> =20 >>>>>> What kernel are you using? pv_ops dom0 kernel doesn't have working= blktap2 yet.. >>>>>> linux-2.6.18-xen has working blktap2 support. >>>>>> >>>>>> -- Pasi >>>>>> =20 >>>>> I'm using the patches maintained by Andrew Lyon that are applied to >>>>> 2.6.31.10. These are supposedly based on the OpenSUSE patches and c= an be >>>>> found at http://code.google.com/p/gentoo-xen-kernel/downloads/list.= I >>>>> need a more recent kernel version so the 2.6.18 dom0 kernel isn't a= n >>>>> option for me. >>>>> >>>>> =20 >>>> Ok. I'm not sure if those OpenSUSE patches have blktap2 support incl= uded? >>>> I know that at least Citrix XenServer, XCP and XCI 2.6.27 kernels do= have blktap2. >>>> >>>> See: >>>> http://wiki.xensource.com/xenwiki/XenDom0Kernels >>>> >>>> =20 >>> More details about the pv_ops dom0 kernel (2.6.31.6 currently): It ha= s initial version >>> of blktap2 patches, but they'd need some debugging, because they're n= ot yet working. >>> >>> -- Pasi >>> =20 >> >> Looking under drivers through a make menuconfig on the pvops kernel I >> don't see an entry for blktap2. I just see the entry for blktap. I kno= w >> that blktap2 was supposed to replace blktap but in the Novell patches >> they are two separate config options and I don't seem to be seeing the >> second on in the pvops kernel. Do I just enable blktap under drivers a= nd >> use tap:tapdisk: in the domU config to use blktap2? >> >> =20 > See: > http://git.kernel.org/?p=3Dlinux/kernel/git/jeremy/xen.git;a=3Dshortlog= ;h=3Dxen/master > > Commits like: > > 2009-12-10 Jeremy Fitzhardinge Merge branch 'xen/dom0/backend/blktap2'= into xen/master > 2009-12-10 Jeremy Fitzhardinge xen/blktap2: don't init on non-Xen syst= em > 2009-12-04 Ian Campbell blktap: cleanup usage of sysfs > 2009-12-04 Ian Campbell blktap: wean off of use of the BlkBack pagefla= g. > 2009-12-04 Ian Campbell Port blktap2 from 2.6.18 to tip. > 2009-12-04 Ian Campbell Add build infrastrucuture for blktap2. > 2009-12-04 Ian Campbell patch 03-blktap2-patch > 2009-12-04 Ian Campbell patch 02-blkback-pagemap-patch > 2009-12-04 Ian Campbell patch 01-blktap-patch > > I haven't tried it myself yet.. > =20 It is pretty broken at present, and I'll probably commit a change to=20 disable it for now. Fortunately it looks like Daniel Stodden is going=20 to have a crack at fixing it up. J