From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <5142EBBC.6030300@redhat.com> Date: Fri, 15 Mar 2013 10:37:00 +0100 From: Zdenek Kabelac MIME-Version: 1.0 References: <513090CA.8050904@pse-consulting.de> <5136F2F1.3020202@pse-consulting.de> <5136F738.1010707@hoster-ok.com> <5137091A.4070300@pse-consulting.de> <51370DDB.5010002@hoster-ok.com> <5137137B.5010800@pse-consulting.de> <5137267A.7040000@hoster-ok.com> <513733C0.2020207@pse-consulting.de> <5137447B.7030906@hoster-ok.com> <514097C8.4030602@pse-consulting.de> <5140AF20.7060406@hoster-ok.com> <5140B968.4030800@pse-consulting.de> <5140C5E2.8050203@hoster-ok.com> <514247D5.8000605@pse-consulting.de> <5142E33F.2060002@redhat.com> <5142E9DD.30701@hoster-ok.com> In-Reply-To: <5142E9DD.30701@hoster-ok.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] LVM snapshot with Clustered VG [SOLVED] 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="us-ascii"; format="flowed" To: Vladislav Bogdanov Cc: Andreas Pflug , LVM general discussion and development Dne 15.3.2013 10:29, Vladislav Bogdanov napsal(a): > 15.03.2013 12:00, Zdenek Kabelac wrote: >> Dne 14.3.2013 22:57, Andreas Pflug napsal(a): >>> On 03/13/13 19:30, Vladislav Bogdanov wrote: >>>> >>>>> Is there a way to find out if a LV is locked exclusively? lvs >>>>> displaying >>>>> -e-- instead of -a-- would be nice. Seems not even lvdisplay knows >>>>> about >>>>> exclusive locking. >>>> That would break other tools which rely on their output. F.e. cluster >>>> resource agents of libvirt (yes, it runs lvm tools rather then using >>>> API, which is not yet complete btw). As I also need to obtain this >>>> information, I think about writing simple tool (f.e. clvm_tool) which >>>> would display needed info. >>>> >>>> As a workaround you can run lvchange -aly without force parameter. If it >>>> succeeds, the volume is locked in a shared mode, otherwise it is locked >>>> exclusively. >>> >>> Hm, thats one ugly workaround... >>> How about a clvmd option, something like -l to list all locks and exit. >>> >> >> >> I think - the extension to 'lvs' command could be relatively simple >> (adding a new column) > > Yes, that's correct. > >> >> You may query for exclusive/local activation on the node. >> (So you cannot just tell on which other node is the device active, >> but you could print about these states: >> >> active exclusive local >> active exclusive >> active local >> active > > You also may poll all know nodes, but that is a hack too. > > That's why I prefer to have this as a separate tool (with dlm_tool-like > params and output) which lists node IDs and lock mode. Unfortunately do > not have power to write it now. > > Are core LVM devels interested in these two features: lock conversion > and managing remote node locks? If yes, then I can (hopefully) prepare > git patches next week. I'm not quite sure what do you mean by 'managing remote node locks' ? Current login behind lvm command is - You could activate LVs with the above syntax [ael] (there is a tag support - so you could exclusively activate LV on remote node in via some configuration tags) And you want to 'upgrade' remote locks to something else ? What would be the use-case you could not resolve with current command line args? Is that supported by dlm (since lvm locks are mapped to dlm)? How would you resolve error path fallbacks ? Also I believe the clvmd protocol is out of free bits for extension, so how the protocol would look like ? Zdenek