From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yura Pismerov Subject: Re: [Xen-users] How to share data between guest domains Date: Mon, 20 Mar 2006 08:49:44 -0500 Message-ID: <441EB2F8.3080403@armorware.net> References: <1142710436.15319.1.camel@localhost> <441C7352.7030401@hcsd.de> <441CB16E.6090901@freemail.hu> <200603182119.31607.javier@guerrag.com> <2967.67.184.68.1.1142737228.squirrel@67.184.68.1> <62b0912f0603200445q6667d3c9q53bd8e9ce48fcedf@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <62b0912f0603200445q6667d3c9q53bd8e9ce48fcedf@mail.gmail.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org I found that using NFS for things like this makes much more sense. You can run the domU with NFS root (read-only) and map certain areas you need read/write to tmpfs by mounting them with "mount --bind" in Linux). For example, if I use NFS root and want my /etc be writable I can always write its content to a tmpfs mounted area and run "mount --bind /tmpfs/etc /etc". This also will solve problems with centralized package updates when not only /usr is being updated, but some other areas (eg. /etc, /var/lib). You want those areas be shared between domU's as well. Molle Bestefich wrote: >Todd D. Esposito wrote: > > >>However, on that note, I wonder if you could mount the same file system, >>say something like /usr, into multiple domU's READ ONLY. >> >> > >That works for me. > >What doesn't work is mounting that file/device READ/WRITE in one domU >to update the filesystem. For that, I have to take down *all* domUs. >Not good... > >(When I try I get a vbd: error saying "already in use".) > >(I know about caching and that I need eg. a cluster-aware filesystem >to do this.) > >I've spent a couple of hours hunting through various Xen source files. > There's a lot of Python functions that are only 3-5 lines long and >which does little else than calling the next function, which makes it >very hard to figure out what's going on :-/. > >Could one of you devel guys please let me know where I need to go to >remove this silly limitation? :-) > >_______________________________________________ >Xen-users mailing list >Xen-users@lists.xensource.com >http://lists.xensource.com/xen-users > > -- Yuri Pismerov, System Administrator Armor Technologies (Canada) Inc. P: 905 305 1946 (x.3519) http://www.armorware.net Privacy Protection Guaranteed!