During a snapshot, if an fsfreeze fails, for example due to https://access.redhat.com/solutions/7087713, the system will just continue to loop trying to fsfreeze again and again, until it reaches the snapshot deadline.

{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.088429Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.088465Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.126064Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.126094Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.165165Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.165206Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.217425Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.217457Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.288655Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.288684Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.402307Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.402336Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.593687Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.593725Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:14.949590Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:14.949619Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:15.625161Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:15.625201Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","level":"error","msg":"Failed to freeze vmi, virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","pos":"manager.go:1629","timestamp":"2024-09-18T05:50:17.074487Z"}
{"component":"virt-launcher","kind":"","level":"error","msg":"Failed to freeze vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:269","reason":"virError(Code=1, Domain=10, Message='internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': failed to open /mnt/test: Permission denied')","timestamp":"2024-09-18T05:50:17.074518Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
{"component":"virt-launcher","kind":"","level":"info","msg":"Synced vmi","name":"rhel-8","namespace":"homelab","pos":"server.go:208","timestamp":"2024-09-18T05:50:19.537987Z","uid":"ce92b1aa-79e5-4136-a220-1ed24e10a819"}
.....
repeats over and over

# oc get virtualmachinesnapshot snapshot-aquamarine-hare-33 -o yaml
apiVersion: snapshot.kubevirt.io/v1alpha1
kind: VirtualMachineSnapshot
metadata:
  creationTimestamp: "2024-09-18T05:50:13Z"
  finalizers:
  - snapshot.kubevirt.io/vmsnapshot-protection
  generation: 4
  name: snapshot-aquamarine-hare-33
  namespace: homelab
  ownerReferences:
  - apiVersion: kubevirt.io/v1
    blockOwnerDeletion: false
    kind: VirtualMachine
    name: rhel-8
    uid: 1bd72695-04e8-450e-9998-46b62dd92895
  resourceVersion: "1011220"
  uid: c349c24a-7d0a-4db2-b57d-84c947388328
spec:
  source:
    apiGroup: kubevirt.io
    kind: VirtualMachine
    name: rhel-8
status:
  conditions:
  - lastProbeTime: null
    lastTransitionTime: "2024-09-18T05:55:13Z"
    reason: snapshot deadline exceeded
    status: "False"
    type: Progressing
  - lastProbeTime: null
    lastTransitionTime: "2024-09-18T05:50:14Z"
    reason: Not ready
    status: "False"
    type: Ready
  - lastProbeTime: null
    lastTransitionTime: "2024-09-18T05:55:13Z"
    reason: snapshot deadline exceeded
    status: "True"
    type: Failure
  indications:
  - Online
  - GuestAgent
  phase: Failed
  readyToUse: false
  sourceUID: 1bd72695-04e8-450e-9998-46b62dd92895

4.16.2

100%

Inside the Guest:
$ mount -o bind /var/ /mnt/test/
$ chcon -t rpm_var_lib_t /mnt/test
$ mount -o remount,ro,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota,suid /mnt/test/
eclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)

"Deadline exceeded", doesn't say where we were stuck at when the deadline was reached.

Proper error propagation, tell the user there was a problem freezing the guest fs