Which version of CloudStack are you using? Seems in 4.2, Wido enhanced RBD a lot, qemu-img itself can copy volume from NFS to RBD without temporary copying to /tmp folder.
> -----Original Message----- > From: Andrei Mikhailovsky [mailto:and...@arhont.com] > Sent: Wednesday, March 19, 2014 5:00 PM > To: dev@cloudstack.apache.org > Subject: ACS and KVM uses /tmp for volumes migration and templates > > Hi guys, > > I was wondering if this is a bug? > > I've noticed that during volume migration from NFS to RBD primary storage > the volume image is first copied to /tmp and only then to the RBD storage. > This seems silly to me as one would expect a typical volume to be larger than > the host's hard disk. Also, it is a common practice to use tmpfs as /tmp for > performance reasons. Thus, a typical host server will have far smaller /tmp > folder than the size of an average volume. As a result, volume migration > would break after filling the /tmp and could probably cause a bunch of issue > for the KVM host itself as well as any vms running on the server. > > It also seems that the /tmp is temporarily used during a template creation . > > My setup: > > ACS 4.2.1 > Ubuntu 12.04 with KVM > RBD + NFS for Primary storage > NFS for Staging and Secondary storage > > > Thanks > > Andrei
