Ilya, i have followed the instructions on ceph website and it worked perfectly well. The only addition is to enable rbd caching in the ceph.conf
Andrei ----- Original Message ----- > From: "ilya musayev" <ilya.mailing.li...@gmail.com> > To: dev@cloudstack.apache.org > Sent: Thursday, 19 February, 2015 10:21:22 AM > Subject: Re: Libvirt & RBD caching > Logan > Side note: it would help great if you can post your notes/guide on > setting up Ceph as primary with CloudStack. > There arent any docs out there. > Thanks > ilya > On 2/18/15 12:00 PM, Logan Barfield wrote: > > Our current deployment is KVM with Ceph RBD primary storage. We > > have > > rbd_cache enabled, and use "cache=none" in Qemu by default. > > > > I've been running some tests to try to figure out why our write > > speeds > > with FreeBSD are significantly lower than Linux. I was testing both > > RBD and local SSD storage, with various cache configurations. Out > > of > > all of them the only one that performed close to our standard Linux > > images was local SSD, Qemu cache=writeback, FreeBSD gpt journal > > enabled. > > > > I've been reading on various lists the reasons and risks for > > cache=none vs cache=writeback: > > - cache=none: Safer for live migration > > - cache=writeback: Ceph RBD docs claim that this is required for > > data > > integrity when using rbd_cache > > > > From what I can tell performance is generally the same with both, > > except in the case of FreeBSD. > > > > What is the current line of thinking on this? Should be using > > 'none' > > or 'writeback' with RBD by default? Is 'writeback' considered safe > > for live migration?
