On 05/13/2013 09:55 AM, Gregory Farnum wrote:
On Mon, May 13, 2013 at 9:10 AM, Harald Rößler <harald.roess...@btd.de> wrote:
Hi Together
is there a description of how a shared image works in detail? Can such
an image can be used for a shared file system on two virtual machine
(KVM) to mount. In my case, write on one machine and read only on the
other KVM.Are the changes are visible on the read only KVM?
The image is just striped across RADOS objects. In general you can
think of it behaving exactly like a hard drive connected to your
computer over iSCSI — a proper shared FS (eg, OCFS2) will work on top
of it, but there's no magic that makes running an ext4 mount on two
machines work...
Also, if you're talking about RBD images, there can be VM-side caching,
and so there's no guarantee that writes from the writing VM will be seen
by the readonly VM. rbd isn't meant for sharing. You want a filesystem
for things like that.
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