On Mon, Jan 25, 2016 at 11:10:16AM -0500, Cole Robinson wrote: > On 01/24/2016 08:15 AM, Michael A Cooper wrote: > > Hey Guys, > > > > How is everyone? I am not sure how to word this question but here > > goes. I have a 3 server setup and I created a nfs share so that I could do > > Live Migration across the servers. So when I create the vm with qcow2 > > everything goes smooth and quick, but when I try to create with .img (Raw) it > > takes forever to create the file. Also when I try and delete an .img file (20 > > gb) it has been over 20 minutes to delete it, any ideas? > > > > qcow2 files are sparse/not-fully-allocated, so while you request 20GB it's > probably only writing a few MB. The rest is filled in as the VM writes to it. > > raw can do sparse as well, but 1) virt-manager doesn't default to it if you > choose raw which means it is allocating the full 20GB, and 2) even if you do > choose sparse the semantics are a bit different for NFS, not sure if it > affects your use case though: > https://serverfault.com/questions/731632/does-nfs-and-smb-support-sparse-files I suspect in this case, the shortcoming of NFS is that it doesn't support posix_fallocate, so it has to be emulated by glibc (although NFS 4.2 does support it, finally). This bug is also relevant if you're using RHEL 7.2: https://bugzilla.redhat.com/show_bug.cgi?id=1265196 Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top _______________________________________________ virt-tools-list mailing list virt-tools-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/virt-tools-list
