Unable to attach multiple datadisk to a vm running on a kvm arm64 host

[kiranchavala]

problem

Unable to attach multiple datadisk to a vm running on a kvm arm64 host

versions

ACS 4.22
KVM Ubuntu 24.0.4

The steps to reproduce the bug

1. Launch a vm on arm64 host

2. Attach multiple data disks to the vm

3. Exception thrown after trying to attach a second data disk

2025-12-23 06:24:24,030 INFO  [kvm.storage.LibvirtStorageAdaptor] (AgentRequest-Handler-2:[]) (logid:dcd66ca9) Attempting to create volume a7831113-9d77-4945-b8fc-ab4b9bb66e9c (NetworkFilesystem) in pool 1a655239-1930-3a48-b0c5-9069065c283d with size (5.00 GB) 5368709120
2025-12-23 06:24:24,123 INFO  [kvm.storage.LibvirtStorageAdaptor] (AgentRequest-Handler-3:[]) (logid:dcd66ca9) Trying to fetch storage pool 1a655239-1930-3a48-b0c5-9069065c283d from libvirt
2025-12-23 06:24:24,128 INFO  [kvm.storage.LibvirtStorageAdaptor] (AgentRequest-Handler-3:[]) (logid:dcd66ca9) Trying to fetch storage pool 1a655239-1930-3a48-b0c5-9069065c283d from libvirt
2025-12-23 06:24:24,153 WARN  [kvm.storage.KVMStorageProcessor] (AgentRequest-Handler-3:[]) (logid:dcd66ca9) Failed to attach device to i-2-131-VM: internal error: No more available PCI slots
 

Workaround

Stop/start the vm and attach the second data disk , no exception thrown

What to do about it?

Cloudstack should support the attachment of multiple data disk to a vm on kvm arm64 host