Change clone strategy to avoid PowerStore snapshot limits

[coulof]

What this PR does / why we need it:
PowerStore has a limit of 32 to 64 writable snapshots which prevents to create more VMs from a base OS.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

Release note:

* Dell PowerStore uses `cloneStrategy: copy` over `csi-clone` to avoid array snapshot limits

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[akalenyu]

So CSI/snapshot clones normally create ephemeral snapshots, which should keep us within limits.
Could you please attach some PowerStore source? I am probably misunderstanding the issue.

I want to ensure I poke at this a bit, since doing host assisted clones all over is going to be a major hit for anyone who uses this solution.

[coulof]

So CSI/snapshot clones normally create ephemeral snapshots, which should keep us within limits. Could you please attach some PowerStore source? I am probably misunderstanding the issue.

I want to ensure I poke at this a bit, since doing host assisted clones all over is going to be a major hit for anyone who uses this solution.

In PowerStore, a PVC restore from a Snapshot is actually a writable Snapshot. There are limited number of writable snapshot per LUN therefore we have to switch to host copy.

[akalenyu]

So CSI/snapshot clones normally create ephemeral snapshots, which should keep us within limits. Could you please attach some PowerStore source? I am probably misunderstanding the issue.
I want to ensure I poke at this a bit, since doing host assisted clones all over is going to be a major hit for anyone who uses this solution.

In PowerStore, a PVC restore from a Snapshot is actually a writable Snapshot. There are limited number of writable snapshot per LUN therefore we have to switch to host copy.

In that case, you also want to not use snapshots as golden sources (many VMs will restore from them), right

containerized-data-importer/doc/onboarding-storage-provisioners.md

Lines 18 to 19 in 1360dfd

	- Ceph rbd scales better when golden sources are stored as snapshots (more info in [clone-from-volumesnapshot-source](./clone-from-volumesnapshot-source.md))
	https://github.com/kubevirt/containerized-data-importer/blob/c6089cbcb01ab58e75b25be1770ce0f3f4625014/pkg/storagecapabilities/storagecapabilities.go#L109-L112

But my worries remain, host-assisted is a big hammer,
But other things could break too, for example, you're saying the number of VMSnapshot/VMRestores one can make is also limited?