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Re: KVM NFS template image

Developers please correct me... but as far as I remember there is a garbage collector which does remove the templates from primary storage once they are not needed (i.e. have no more "child VMs"). This is controlled by the global setting "storage.template.cleanup.enabled".

Dag Sonstebo
Cloud Architect

On 16/11/2018, 22:51, "ran huang" <ran.huang134@xxxxxxxxx> wrote:

    Hi Andrija,
    Thanks for the clarification and quick response
    On 11/16/2018 02:15 PM, Andrija Panic wrote:
    > Hi Ran,
    > templates stays on Primary Storage "forever", at least for NFS (they are
    > moved from Secondary to Primary when you deploy a very first VM from
    > specific template). All VMs have this templates qcow2 as baking (parent)
    > image.
    > This template is a qcow2 copy of a file from Secondary Storage - and is
    > considered a "parent" image, from which all child images  (VM volumes) are
    > created - as you stated baking file (qcow linked clones, in official
    > terminology)
    > you can have i.e. 100 VMs all linking (having it's backing file...) to a
    > template qcow2 file.
    > So in other words, it's not supposed to be removed.
    > Does this make sense?
    > Cheers
Amadeus House, Floral Street, London  WC2E 9DPUK

> On Fri, 16 Nov 2018 at 22:38, ran huang <ran.huang134@xxxxxxxxx> wrote:
    >> Greetings All,
    >> For qcow2 format images, when creating a new VM in KVM, the template
    >> image is copied from secondary storage to primary storage, and the root
    >> volume image is created with the template image as a backing file.
    >> But when I break this backing chain on primary(expunge VM or revert to a
    >> snapshot previously created on the root volume image), the template
    >> image is not deleted.
    >> Might I ask how is the template image going to be cleaned from the
    >> primary storage?
    >> addendum:
    >> CS ver 4.9.2 on CentOS 7.2
    >> regards,
    >> Ran