Description

Router crashed while customer was running prechecks as a part of preparing the device for an upcoming maintenance. After the crash, the devices rebooted and came online in amnesiac mode with an older Junos code. The router booted to 18.3R1-S5.1 instead of customer version 20.3X2.1.  

Symptoms

1] No alarms or errors other the device prints a message indicating that its in amnesiac mode

 

labuser@labrouter> show chassis alarms 

Aug 15 01:21:18

No alarms currently active

 

2] No errors reported in "show vmhost version or show vmhost snapshot" outputs

 

labuser@labrouter> show vmhost version 

Aug 15 01:37:34

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

Current boot disk: Secondary

Current root set: p

UEFI  Version: CBDE_P_RIO1_00.25.01

 

Secondary Disk, Snapshot Time: <fresh install>

 

Version: set p

VMHost Version: 3.1861

VMHost Root: vmhost-x86_64-18.3R1-S1-20181010_1124_builder

VMHost Core: vmhost-core-x86-64-18.3R1-S5.1

kernel: 3.10.100-ovp-rt110-WR6.0.0.31_preempt-rt

Junos Disk: junos-install-acx-x86-64-18.3R1-S5.1

 

Version: set b

VMHost Version: 3.1861

VMHost Root: vmhost-x86_64-18.3R1-S1-20181010_1124_builder

VMHost Core: vmhost-core-x86-64-18.3R1-S5.1

kernel: 3.10.100-ovp-rt110-WR6.0.0.31_preempt-rt

Junos Disk: junos-install-acx-x86-64-18.3R1-S5.1

 

 

labuser@labrouter> show vmhost snapshot 

Aug 15 01:37:49

UEFI  Version: CBDE_P_RIO1_00.25.01

 

Secondary Disk, Snapshot Time: <fresh install>

 

Version: set p

VMHost Version: 3.1861

VMHost Root: vmhost-x86_64-18.3R1-S1-20181010_1124_builder

VMHost Core: vmhost-core-x86-64-18.3R1-S5.1

kernel: 3.10.100-ovp-rt110-WR6.0.0.31_preempt-rt

Junos Disk: junos-install-acx-x86-64-18.3R1-S5.1

 

Version: set b

VMHost Version: 3.1861

VMHost Root: vmhost-x86_64-18.3R1-S1-20181010_1124_builder

VMHost Core: vmhost-core-x86-64-18.3R1-S5.1

kernel: 3.10.100-ovp-rt110-WR6.0.0.31_preempt-rt

Junos Disk: junos-install-acx-x86-64-18.3R1-S5.1

 

 

3] However, one of the DISK is missing in "show vmhost hardware " output

 

P2145550@IRNHTXOF2QW> show vmhost hardware 

Aug 16 00:24:39

Compute cluster: rainier-re-cc

 

 Compute node: rainier-re-cn          

  Hardware inventory:

   

  Item    Capacity       Part number        Serial number       Description

  DIMM 0   16384 MB       VL41A2G63A-N6SB-JUN    0x52978325        DDR4 2133 MHz

  DIMM 1   16384 MB       VL41A2G63A-N6SB-JUN    0x52978337        DDR4 2133 MHz

  Disk1   100 GB       StorFly-VSFBM6CC100G   P1T14005244403300124   SLIM SATA SSD

 

 

4] Vmhost snapshot creation failing and reporting that the Router is booted with secondary disk

 

Labroot@labhost> request vmhost snapshot partition   

Aug 16 00:36:31

warning: All existing data on the target media will be lost

Proceed ? [yes,no] (no) yes 

Aug 16 00:36:37

 

warning: Proceeding with vmhost snapshot partition

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

Already running from secondary disk.

Please try recovery option to restore primary!

Snapshot aborted.

 

5] Routing Engine Console logs or dmesg output reports issues in accessing Primary Disk

 

ata1: SATA max UDMA/133 abar m2048@0x90f00000 port 0x90f00100 irq 81

ata2: SATA max UDMA/133 abar m2048@0x90f00000 port 0x90f00180 irq 81

ata3: DUMMY

ata4: DUMMY

ata5: DUMMY

ata6: DUMMY

 

ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)

ata2.00: FORCE: horkage modified (noncq)

ata2.00: ATA-9: StorFly VSFBM6CC100G-JUN1, 0626-000, max UDMA/133

 

ata1: COMRESET failed (errno=-16)

ata1: link is slow to respond, please be patient (ready=0)

ata1: COMRESET failed (errno=-16)

ata1: link is slow to respond, please be patient (ready=0)

ata1: COMRESET failed (errno=-16)

ata1: limiting SATA link speed to 3.0 Gbps

ata1: COMRESET failed (errno=-16)

ata1: reset failed, giving up

 

scsi 1:0:0:0: Direct-Access   ATA   StorFly VSFBM6CC 0626 PQ: 0 ANSI: 5

sd 1:0:0:0: Attached scsi generic sg0 type 0

sd 1:0:0:0: [sda] 195371568 512-byte logical blocks: (100 GB/93.1 GiB)

sd 1:0:0:0: [sda] Write Protect is off

sd 1:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

sda: sda1 sda2 sda3 sda4 sda5 sda6

sd 1:0:0:0: [sda] Attached SCSI disk

Solution

The above Kernal Logs (5) indicates that the device is failing to read the primary disk (ata1, sd 0:0:0:0). As primary disk failed, system renamed secondary disk (ata2, address sd 1:0:0:0) ) as “sda” instead of “sdb”. Hence, no alarms reported stating that the device was booted from secondary disk

 

In this case, customer did not created vmhost snapshot previously, hence system booted in an older code and in amnesiac mode.

Replace Routing Engine to resolve the issue 

Modification History

2024-08-20 : Article Created