Symptom: top shows wa at 15-20%, and juno-main slows down.
Cause: The QCOW2 backing file is on a slow rotational HDD or a network share.
Fix:
<driver name='qemu' type='qcow2' cache='writeback'/>
When running top on your vQFX 20.2R1.10 QCOW2 image, you may encounter: vqfx202r110reqemuqcow2 top
[PC1] --- (ge-0/0/0) [vQFX-1] (ge-0/0/1) --- [vQFX-2] --- [PC2]
Quick config snippet (on vQFX-1):
set interfaces ge-0/0/0 unit 0 family inet address 10.0.0.1/24
set interfaces ge-0/0/1 unit 0 family inet address 10.0.1.1/24
set protocols ospf area 0 interface ge-0/0/0.0 passive
set protocols ospf area 0 interface ge-0/0/1.0
| Field | Value |
|-------|-------|
| Filename | vqfx202r110reqemuqcow2 |
| Device | Juniper vQFX (virtual QFX series switch) |
| Version | 20.2R1.10 |
| Format | QCOW2 (QEMU Copy-On-Write) |
| Use case | EVE-NG, GNS3, or manual QEMU/KVM lab environments | Symptom: top shows wa at 15-20%, and juno-main
This image emulates a Juniper QFX switch, used for data center fabric, EVPN-VXLAN, and advanced Layer 2/Layer 3 testing. <driver name='qemu' type='qcow2' cache='writeback'/>
The RE image provides the standard CLI (cli). However, users often try to console into the PFE image. This will fail. The PFE console generally outputs binary data or debugging logs, not a login prompt. You should only manage the device via the RE.
When you download a vQFX appliance from Juniper’s official site, you typically get a .qcow2 file. Running top inside this VM gives you real-time insight into how the virtual switch consumes CPU and memory resources.