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[MX] How to clear the alarm, 'BIOS Boot from secondary flash'



Article ID: KB36840 KB Last Updated: 29 Apr 2021Version: 1.0

This article explains how to clear the "BIOS Boot from secondary flash" system alarm in an MX device.


The following active alarm is seen:

1 alarms currently active
Alarm time               Class  Description
2021-04-14 05:33:52 UTC  Minor  VMHost 1 BIOS Boot from secondary flash

The probable cause is that the "host" has booted up from secondary flash (RE bootloader), rather than the primary one.


To resolve this issue, perform the following procedure via CLI/Console.
In this example, RE1 is booted from the secondary flash. Hence, the procedure below is executed on Routing Engine 1.

  1. Reboot RE1 from backup Disk:

    labroot@re1> request vmhost reboot disk 2 
    Reboot the vmhost ? [yes,no] (no) yes 
    warning: Rebooting re1
    Initiating vmhost reboot...  Cmos Write successfull
    Cmos Write successfull for Boot_retry
    Cmos Write successfull for Boot_retry
  2. After the reboot, login to Routing Engine. Since you are on Disk 2, a new alarm will appear:

    FreeBSD/amd64 (re1) (ttyu0)
    login: labroot
    Local password:
    --- JUNOS 16.1X8.3 Kernel 64-bit  JNPR-10.3-20180310.ba55661_buil
    Note: VM Host is Currently running from alternate disk
    2 alarms currently active
    Alarm time               Class  Description
    2021-04-14 06:32:10 UTC  Minor  VMHost 1 Boot from alternate disk
    2021-04-14 05:33:52 UTC  Minor  VMHost 1 BIOS Boot from secondary flash
  3. Recover the Primary Partition:

    labroot@re1> request vmhost snapshot recovery partition    
    warning: All existing data on the target media will be lost
    Proceed ? [yes,no] (no) yes 
    warning: Proceeding with vmhost snapshot partition
    Current root details,           Device sdb, Label: jrootp_S, Partition: sdb3
    sh /etc/install/ P
    Estimated raw partition sizes:
    ESP/SPARE/ROOTP/ROOTB/PV/SWAP: 954, 1908, 4770, 4770, 34346, 477
    Aligned, Estimated raw partition sizes:
    ESP/SPARE/ROOTP/ROOTB/PV/SWAP: 952, 1904, 4768, 4768, 34344, 472
    Estimated LVM partition sizes:
    PV/LVMROOT/LVMJUNOS/LVMVM/LVMSPARE: 42968, 3437, 34374, 6445, 0
    Aligned, Estimated LVM partition sizes:
    PV/LVMROOT/LVMJUNOS/LVMVM/LVMSPARE: 42968, 3432, 34368, 6440, 0
    Aligned, adjusted raw and LVM partition sizes:
    ESP/SPARE/ROOTP/ROOTB/PV/SWAP: 255, 255, 2048, 2048, 42968, 128
    PV/LVMROOT/LVMJUNOS/LVMVM/LVMSPARE: 42968, 3432, 32784, 6440, 304
    Snapshot admin context from current boot disk to target disk ...
    Proceeding with snapshot on primary disk
    Mounting device in preparation for snapshot...
    Cleaning up target disk for snapshot ...
    Creating snapshot on target disk from current boot disk ...
    Primary disk is recovered now. Please issue "request vmhost reboot" to boot from the primary disk.
    Software snapshot done
  4. After the successful completion of step 3, power-off/reboot RE1 so that it can now boot from primary disk.

    labroot@re1> request vmhost power-off 
    Power-off the vmhost ? [yes,no] (no) yes 
    Initiating vmhost shutdown...  ok
    Initiating Junos shutdown...  shutdown: [pid 5537]
    Shutdown NOW!
    *** FINAL System shutdown message from root@re1 ***              
    System going down IMMEDIATELY    
    labroot@re0> request vmhost power-on other-routing-engine 
    Apr 14 06:37:52
    Routing Engine 1 power-on initiated, use "show chassis routing-engine" to verify
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