Diagnostics

Read-only checks that run on a host and return their output.

Diagnostics are a curated set of read-only commands that run on a host and return what they printed. They are available from a host’s Diagnostics tab in Infrastructure, and from the CLI.

Hyperion[vsnode1]> show diagnostics
Hyperion[vsnode1]> run diagnostic <key>

Every one is read-only and safe to run at any time, including during an incident.

Why it is a fixed catalogue

The set is fixed, and that is the security boundary rather than an inconvenience.

Diagnostics run with privilege on the host. If the platform accepted an arbitrary command it would be an arbitrary-execution endpoint wearing a diagnostic label — and the restrictions that make root shell access an authorized, audited act would be meaningless, because there would be an unaudited way around them.

The commands are also re-validated on the host, not only chosen in the console. A check the caller could bypass is not a check.

The catalogue

System

Key Shows
sys.uptime Uptime and load
sys.os OS release
sys.kernel Kernel version
sys.cpu CPU detail
sys.memory Memory
sys.processes Top processes
sys.logins Logins

Storage

Key Shows
stor.lsblk Block devices
stor.df Filesystem usage
stor.mounts Mounts
stor.smart SMART health
stor.lvm LVM volumes and groups
stor.zfs ZFS pools
stor.mdstat Software RAID
stor.iscsi iSCSI sessions

stor.smart is the one to run when a disk is suspected. stor.df catches the classic cause of a host behaving strangely: a full filesystem.

Network

Key Shows
net.addr Addresses
net.route Routes
net.linkstats Link statistics
net.bonds Bonds
net.arp Neighbours
net.ovs Virtual switch state
net.ovnsb Chassis registration
net.geneve Overlay tunnels
net.bfd BFD sessions
net.sockets Listening sockets

net.geneve is the first thing to check on an overlay problem — silence on an overlay fabric means it is broken. net.bonds tells you whether a bond actually has both members up, which is not the same as the uplink reporting ready.

Virtualization

Key Shows
virt.domains Domains on this host
virt.nodeinfo Hypervisor node info
virt.versions Component versions
virt.capabilities What the host can do
virt.iommu IOMMU status

virt.iommu is the one to check when PCI passthrough will not work.

Services and logs

Key Shows
svc.agent Agent status
svc.libvirtd Hypervisor daemon status
svc.failed Failed units
svc.journal Agent journal
log.agent, log.libvirtd, log.ovn, log.frr, log.openvswitch, log.iscsi Component logs

svc.failed is a good first command on a host that is misbehaving without an obvious cause.

Packet capture

Separately from the catalogue, a host’s Packet capture tab captures traffic on an interface and lets you download it — for when the question is what is actually on the wire.

Logging diagnostics

The control plane also exposes its own logging state, so support can see what it has been recording without needing shell access to a controller.

When diagnostics are not enough

If you need something the catalogue does not cover, that is what root shell access is for — an explicit, time-limited, audited escalation rather than a widened diagnostic endpoint.