Agreed. The "getting started" instructions walk you through creating most of a cluster then adding once more node piecemeal, but this seems needlessly complex for a beginner. I found the easiest way to get up and running was with three VMs with one or two logical partitions for OSDs on each and each of the three also running a MON process. There are fewer hosts to manage and you can easily have a static hosts file that handles name resolution for everything. Also, you can do it all on one logical network. For educational purposes, there's no need to separate traffic. Of course, as noted, most of that advice is out the window once you start to plan for a cluster that has any kind of decent performance. Dan Dan Geist dan(@)polter.net ----- Original Message ----- From: "Christian Balzer" <chibi@xxxxxxx> Cc: ceph-users@xxxxxxxxxxxxxx Sent: Tuesday, October 21, 2014 6:30:26 AM Subject: Re: real beginner question Hello, On Tue, 21 Oct 2014 10:53:54 +0100 Ranju Upadhyay wrote: > Hi Dan and Ashish, > > Many thanks for the replies. > > It is partly for the learning( and perhaps a production system in > future) that we are playing with ceph. > Learning about Ceph (configuration, operation wise) with VMs is fine. Just don't draw any conclusions from your experiences in there when it comes to performance and other related items, which will be vastly different with real hardware. Production is right out (based on VMs). > I guess, to start with, a simple set up of ,may be 4 vms, where one vm > is admin node and one is mons and 2 are osds ( as suggested in > pre-flight checklist) might be good. > The preflight checklist is unfortunately like so many other documentation slightly dated, the current version of Ceph defaults to a replica size of 3, thus for things to "just work" you will want 3 OSD nodes. Christian > Thanks > Ranju Upadhyay > Maynooth University, Ireland > > -----Original Message----- > From: Dan Geist [mailto:dan@xxxxxxxxxx] > Sent: 20 October 2014 15:11 > To: Ranju Upadhyay > Cc: ceph-users@xxxxxxxxxxxxxx > Subject: Re: real beginner question > > Hi, Ranju. Are you talking about setting up Ceph Monitors and OSD nodes > on VMs for the purposes of learning, or adding a Ceph storage cluster to > an existing KVM-based infrastructure that's using local > storage/NFS/iSCSI for block storage now? > > - If the former, this is pretty easy. Although performance will suffer, > OSDs and Monitors will run fine in VMs, just observe the minimum specs > in the official hardware howtos. I setup my first cluster like this: > > Ubuntu 14.04 Workstation (with LVM) > -Ceph1: 14.04 with Mon1 and OSD using Raw disk access from different > LVM partitions of hypervisor OS -Ceph2: " > -Ceph3: " > -Test VM1: 14.04 desktop with 20G filesystem exposed through RBD to > libvirt. > > What's neat (and was non-obvious) was that simply configuring the KVM > hypervisor as a Ceph client allowed you to leverage its exposed storage > even though the hosts exposing that storage were VMs on the same machine > (horribly non-resilient design, yes, but it helped teach the concepts). > > - If you're looking to do the latter, you can create your Ceph cluster > of nodes adjacent your existing infrastructure, configure your > hypervisor nodes as ceph/rbd clients (and test them with "ceph -w", etc) > then convert/copy the disk images one by one to rbd block images: > http://ceph.com/docs/master/rbd/libvirt/ > http://ceph.com/docs/master/rbd/qemu-rbd/ > > Once you create a few test VMs on local disk and get into the practice > of migrating them over, you'll find it's pretty straightforward with the > commands listed in those pages. > > Dan > > Dan Geist dan(@)polter.net > > > > ----- Original Message ----- > From: "Ranju Upadhyay" <Ranju.Upadhyay@xxxxxxx> > To: ceph-users@xxxxxxxxxxxxxx > Sent: Monday, October 20, 2014 6:23:59 AM > Subject: real beginner question > > Hi list, > > > > This is a real newbie question.(and hopefully the right list to ask to!) > > > > Is it possible to set up ceph in an already virtualized environment? > i.e. we have a scenario here, where we have virtual machine ( as opposed > to individual physical machines) with ubuntu OS on it. We are trying to > create ceph cluster on this virtual machine . (not sure if this is a > sensible thing to do!) > > > > On our effort to install ceph we used vagrant ( came across some notes > through google). We thought that would be the easiest route, as we do > not know anything yet. But we are unsuccessful. We can go as far as > creating a virtual machine but it fails as provisioning stage (i.e. > mons;osds;mdss;rgws etc do not get created) > > > > > > Any suggestions? > > > > > > Thanks > > Ranju Upadhyay > > Maynooth University, > > Ireland. > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ 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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