Hi Mike, Thanks for the update. I will keep a keen eye on the progress. Once you get to the point you think you have fixed the stability problems, let me know if you need somebody to help test. Nick > -----Original Message----- > From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of > Mike Christie > Sent: 21 January 2016 03:12 > To: Nick Fisk <nick@xxxxxxxxxx>; 'Василий Ангапов' <angapov@xxxxxxxxx>; > 'Ilya Dryomov' <idryomov@xxxxxxxxx> > Cc: 'Dominik Zalewski' <dzalewski@xxxxxxxxxxxxx>; 'ceph-users' <ceph- > users@xxxxxxxxxxxxxx> > Subject: Re: CentOS 7 iscsi gateway using lrbd > > On 01/20/2016 06:07 AM, Nick Fisk wrote: > > Thanks for your input Mike, a couple of questions if I may > > > > 1. Are you saying that this rbd backing store is not in mainline and is only in > SUSE kernels? Ie can I use this lrbd on Debian/Ubuntu/CentOS? > > The target_core_rbd backing store is not upstream and only in SUSE kernels. > > lrbd is the management tool that basically distributes the configuration info > to the nodes you want to run LIO on. In that README you see it uses the > target_core_rbd module by default, but last I looked there is code to support > iblock too. So you should be able to use this with other distros that do not > have target_core_rbd. > > When I was done porting my code to a iblock based approach I was going to > test out the lrbd iblock support and fix it up if it needed anything. > > > 2. Does this have any positive effect on the abort/reset death loop a > number of us were seeing when using LIO+krbd and ESXi? > > The old code and my new approach does not really help. However, on > Monday, Ilya and I were talking about this problem, and he gave me some > hints on how to add code to cancel/cleanup commands so we will be able to > handle aborts/resets properly and so we will not fall into that problem. > > > > 3. Can you still use something like bcache over the krbd? > > Not initially. I had been doing active/active across nodes by default, so you > cannot use bcache and krbd as is like that. > > > > > > > > > > > >> -----Original Message----- > >> From: Mike Christie [mailto:mchristi@xxxxxxxxxx] > >> Sent: 19 January 2016 21:34 > >> To: Василий Ангапов <angapov@xxxxxxxxx>; Ilya Dryomov > >> <idryomov@xxxxxxxxx> > >> Cc: Nick Fisk <nick@xxxxxxxxxx>; Tyler Bishop > >> <tyler.bishop@xxxxxxxxxxxxxxxxx>; Dominik Zalewski > >> <dzalewski@xxxxxxxxxxxxx>; ceph-users <ceph-users@xxxxxxxxxxxxxx> > >> Subject: Re: CentOS 7 iscsi gateway using lrbd > >> > >> Everyone is right - sort of :) > >> > >> It is that target_core_rbd module that I made that was rejected > >> upstream, along with modifications from SUSE which added persistent > >> reservations support. I also made some modifications to rbd so > >> target_core_rbd and krbd could share code. target_core_rbd uses rbd > >> like a lib. And it is also modifications to the targetcli related > >> tool and libs, so you can use them to control the new rbd backend. > >> SUSE's lrbd then handles setup/management of across multiple > targets/gatways. > >> > >> I was going to modify targetcli more and have the user just pass in > >> the rbd info there, but did not get finished. That is why in that > >> suse stuff you still make the krbd device like normal. You then pass > >> that to the target_core_rbd module with targetcli and that is how > >> that module knows about the rbd device. > >> > >> The target_core_rbd module was rejected upstream, so I stopped > >> development and am working on the approach suggested by those > >> reviewers which instead of going from lio->target_core_rbd->krbd goes > >> lio->target_core_iblock->linux block layer->krbd. With this approach > >> lio->you > >> just use the normal old iblock driver and krbd and then I am > >> modifying them to just work and do the right thing. > >> > >> > >> On 01/19/2016 05:45 AM, Василий Ангапов wrote: > >>> So is it a different approach that was used here by Mike Christie: > >>> http://www.spinics.net/lists/target-devel/msg10330.html ? > >>> It seems to be a confusion because it also implements > >>> target_core_rbd module. Or not? > >>> > >>> 2016-01-19 18:01 GMT+08:00 Ilya Dryomov <idryomov@xxxxxxxxx>: > >>>> On Tue, Jan 19, 2016 at 10:34 AM, Nick Fisk <nick@xxxxxxxxxx> wrote: > >>>>> But interestingly enough, if you look down to where they run the > >> targetcli ls, it shows a RBD backing store. > >>>>> > >>>>> Maybe it's using the krbd driver to actually do the Ceph side of > >>>>> the > >> communication, but lio plugs into this rather than just talking to a > >> dumb block device??? > >>>> > >>>> It does use krbd driver. > >>>> > >>>> Thanks, > >>>> > >>>> Ilya > > > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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