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Hi<br>
<br>
I am experimenting with different options for distributed storage of
KVM/QEMU virtual machine disk images. I like the simplicity of setup
of sheepdog+corosync, and the homogeneous nature of this
installation (each server is the same). However, given our current
distribution of raw metal servers, I'm not sure it makes sense to us
that every VM host should be running sheepdog. This is because the
raw metal servers we have with the greatest RAM and spare processing
capacity, also have the strongest disk storage which is heavily
utilised. Conversely, we have other raw metal servers that are
shorter on RAM and spare CPU capacity, but have plenty of free disk
space. Our VMs are used for development and testing purposes, and
don't need to be high powered. It therefore seems to make sense to
run sheepdog
on the machines with plenty of free disk space, and the VMs on the
machines with plenty of CPU and RAM.<br>
<br>
I know this is possible with sheepdog, since the qemu driver
supports talking to sheepdog on a remote host, and I've managed to
get that working. What I don't know is, whether there are any plans
to make it possible to migrate VMs backed by such storage from one
sheepdog node to another. This is important for when a sheepdog
server needs to be taken down for maintenance. For example, is it
planned to either (a) allow the choice of remote sheepdog server
backing the guest disk to be changed on-the-fly? (b) Allow a set of
remote sheepdog servers to be specified for the guest disk, allowing
the qemu driver to automatically failover from one to another in the
event the sheepdog node becomes inaccessible? or (c) use a protocol
such as rbd (like Ceph) that supports talking to multiple storage
servers natively?<br>
<br>
Kind regards<br>
<br>
Struan<br>
<br>
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<p style="border-top:1px solid #ccc;padding-top:.5em;"> Struan
Bartlett<br>
NewsNow Publishing Limited </p>
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