Before deploying VMHost devices, such as the MX204, into production, customers may want to ensure that both disks in the routing engines are functioning correctly. Although the disks are currently operational without any active alarms, customers may still wish to perform specific tests to verify their performance and identify any potential issue

1) Concerns about disk health before production deployment.

2) Need to confirm the reliability of both disks through performance checks.

If you'd like to verify whether both disks are functioning properly, any underlying issues with the disks should become evident through following actions.

1) Rebooting the Chassis:

Command: 

request vmhost reboot

This test helps identify any disk-related issues during a full chassis reboot.

2) Rebooting Routing Engine Disks Individually:

Commands:

request vmhost reboot disk 2

request vmhost reboot disk 1

Rebooting the routing engine with each disk one by one to ensure proper operation of both disks individually.

Rebooting with Disk 2 (Secondary Disk):

> show vmhost version

Current root details, Device sda, Label: jrootp_S, Partition: sda3

Current boot disk: Secondary

Current root set: p

UEFI Version: CBEP_P_SUM1_00.15.01

Secondary Disk, Snapshot Time: Thu Apr 27 01:20:20 BST 2023

Version: set p

VMHost Version: 5.2337

VMHost Root: vmhost-x86_64-20.4R3-S6-20230103_2243_builder

VMHost Core: vmhost-core-x86-64-20.4R3-S6.3

kernel: 4.8.28-rt10-WR9.0.0.24_ovp

Junos Disk: junos-install-mx-x86-64-20.4R3-S6.3

Version: set b

VMHost Version: 5.2230

VMHost Root: vmhost-x86_64-19.4R3-S5-20210701_0929_builder

VMHost Core: vmhost-core-x86-64-19.4R3-S5

kernel: 4.8.28-rt10-WR9.0.0.20_ovp

Junos Disk: junos-install-mx-x86-64-19.4R3-S5

Rebooting with Disk 1 (Primary Disk):

> show vmhost version

Current root details,      Device sda, Label: jrootp_P, Partition: sda3

Current boot disk: Primary

Current root set: p

UEFI  Version: CBEP_P_SUM1_00.15.01

Primary Disk, Upgrade Time: Thu Apr 27 01:05:53 BST 2023

Version: set p

VMHost Version: 5.2337

VMHost Root: vmhost-x86_64-20.4R3-S6-20230103_2243_builder

VMHost Core: vmhost-core-x86-64-20.4R3-S6.3

kernel: 4.8.28-rt10-WR9.0.0.24_ovp

Junos Disk: junos-install-mx-x86-64-20.4R3-S6.3

Version: set b

VMHost Version: 5.2230

VMHost Root: vmhost-x86_64-19.4R3-S5-20210701_0929_builder

VMHost Core: vmhost-core-x86-64-19.4R3-S5

kernel: 4.8.28-rt10-WR9.0.0.20_ovp

Junos Disk: junos-install-mx-x86-64-19.4R3-S5

3) Performing Software Upgrades and Downgrades:

• Test the device by performing a couple of software upgrades and downgrades.
• During these operations, the device adds new software sets to the disks and replaces old software, which can reveal any underlying disk issues.

These steps will help identify potential issues with the disks, ensuring the device is fully operational and ready for production.

If a disk actually has an issue, alarms such as the following may appear on the chassis:

> show chassis alarms

2 alarms currently active

Alarm time Class Description

2024-12-19 08:51:32 UTC Minor VMHost RE 0 Disk 1 Missing

2024-12-19 08:50:31 UTC Minor VMHost 0 Boot from alternate disk

To clear these kinds of alarms, please reach out to Juniper Technical Support Center for further investigation.