The ISO library
One ISO library the whole fleet sees at the same path.
Installation media lives in a single library that every host sees at the same path. A VM definition naming an ISO stays valid no matter which host boots it.
That property is the entire point. An ISO reachable on one host and not another produces VMs that start in some places and not others, for reasons nobody enjoys tracking down.
How it works
The library is a plain directory, /var/lib/hyperion/isos, present on every controller — so it
has as many copies as you have controllers.
The active controller exports it over NFS, bound to the cluster VIP. Every non-controller host mounts that export at the same path.
/var/lib/hyperion/isos/ubuntu.iso ← resolves on every host
Binding the export to the VIP rather than to a controller’s own address is what makes it survive failover: when the active controller changes, the VIP moves and the mounts keep resolving. Pointing hosts at a fixed controller would make every controller failover a fleet-wide ISO outage.
Replication between controllers
Controllers replicate the library over the authenticated channel they already use to talk to each other. A peer lists what it has; whatever it is missing, it pulls.
This is deliberately the low-tech option. ISOs are large, immutable and re-downloadable, so pull-what-you-lack is the right amount of machinery — no extra trust relationship, no additional daemon.
Checking it
The library reports its path, the VIP it is exported from, how many ISOs it holds, and a per controller view:
path: /var/lib/hyperion/isos
vip: 10.2.32.240
exportSource: 10.2.32.240:/var/lib/hyperion/isos
isoCount: 2
REPLICAS
NODE ROLE REACHABLE ISOs MISSING
vsnode1 ACTIVE true 2 —
vsnode2 STANDBY true 2 —
vsnode3 STANDBY true 2 —
Missing is the column that matters. A controller missing ISOs is one that has not caught up; if it became active, those ISOs would stop resolving fleet-wide.
Adding an ISO
Upload it from the storage screen. It lands on the controller you uploaded to and replicates to the others.
Large uploads take a while and replication follows, so an ISO is not instantly present everywhere. Check the replica view before relying on it.
Using an ISO
- When creating a VM — attach it as installation media.
- On a running VM — attach or change it from the VM’s console screen, without stopping the VM.
Guest tools can also be mounted from the console screen. See Console and terminal.
Capacity
The library has its own logical volume, /var/lib/hyperion/isos, sized by the installer.
Each controller stores the whole library, so the space is consumed as many times as you have controllers. Delete media you no longer need — an old point release nobody installs is costing space on every controller.
Operating system images
Distinct from ISOs you upload: the deployment can sync operating system images from the software repository it is pointed at.
An air-gapped site has no such repository and uses uploaded ISOs only. See Air-gapped sites.