Fail to start VM from ISO

##### ISSUE TYPE

* Bug Report

##### COMPONENT NAME

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Secondary Storage
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##### CLOUDSTACK VERSION

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CloudStack 4.18.1.0
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##### CONFIGURATION

XCP-NG is used as hypervisor
Secondary storage connected via NFS
##### OS / ENVIRONMENT

##### SUMMARY

Hi!
I faced issue with ISO images.
Whe I mount ISO to multiple VMs, they stop starting in Cloudstack. And from the backend, I can see multiplying ISO SRs on every try to start VM. Some of them has ISO file inside, but most of them hasn't. Please look at screenshots attached.

My general question is can I safely remove (detach/foget/destroy) this empty SRs?
Even if I delete VM, ISO SRs still in the place.
Is there any way to fix issue with VM start?

Thank you in advance!

##### STEPS TO REPRODUCE

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##### EXPECTED RESULTS

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##### ACTUAL RESULTS

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Aucun fichier source, test, commande ou étape reproductible n’est fourni. Commencez par reproduire l’échec de démarrage de la VM avec CloudStack 4.18.1.0, XCP-NG et un stockage secondaire adossé à NFS ; c’est terminé lorsque les VMs démarrent quand des images ISO sont montées, sans créer de ISO SRs vides persistants.

Rédigé par le modèle d'indexation à partir du texte de l'issue.