Description

This article describes scenarios when "Mounting /dev/disk/by-label/efi_P failed - return code - 32" or "Mounting /dev/disk/by-label/efi_S failed - return code - 32" error messages could be seen and clarifies whether any steps should be taken.

Symptoms

The "Mounting /dev/disk/by-label/efi_P failed - return code - 32" error message may appear while doing a snapshot recovery.

root@device>  request vmhost snapshot recovery re1        

re1:
--------------------------------------------------------------------------
warning: Existing data on the target may be lost
warning: Proceeding with vmhost snapshot
Current root details,      Device sda, Label: jrootp_S, Partition: sda3
Snapshot admin context from current boot disk to target disk ...
Proceeding with snapshot on primary disk
Mounting device in preparation for snapshot...
Mounting /dev/disk/by-label/efi_P failed - return code - 32
Vmhost snapshot aborted
Software snapshot failed 

root@device> request vmhost recovery partition re1           

re1:
--------------------------------------------------------------------------
warning: All existing data on the target media will be lost
warning: Proceeding with vmhost snapshot partition
Current root details,      Device sda, Label: jrootp_S, Partition: sda3
sh /etc/install/mk-mtre-partition.sh P
Setting JROOTB_SIZE_MAX=2048
ERROR: Device /dev/ does not exist or is not writable
Usage: mk-mtre-partition.sh DEVICE DEVICE_ROLE
    DEVICE: The device to write the image to, e.g. /dev/sdc
    DEVICE_ROLE: The role of the device, e.g. 'primary' or 'p', 'secondary' or 's'
    PKG_DIR: The dir for content to be picked from
Partitioning failed, vmhost snapshot aborted 

An alarm could also be raised:

root@device> show chassis alarms
1 alarms currently active
Alarm time               Class  Description
xxxx-xxxx-xxxx UTC  Minor  VMHost 1 Boot from alternate set

Solution

The error message "Mounting /dev/disk/by-label/efi_<P|S> failed - return code - 32" typically indicates a problem with mounting the EFI system partition (ESP) during the boot process. 

  • EFI System Partition (ESP): This partition is crucial for booting systems with UEFI firmware. It contains essential files like the boot loader (e.g., GRUB, UEFI firmware updates, etc.).
  • Return Code 32: This specific error code usually signifies a permission-related issue. It could mean that the user or the system doesn't have the necessary rights to access or mount the partition.

Possible Causes:

  • File System Corruption: The file system on the ESP might be corrupted, making it unreadable or unmountable.
  • Hardware Issues: Problems with the hard drive or SSD where the ESP is located can also cause mounting failures.

Troubleshooting:

Output of "show vmhost logs kern.log" and "show vmhost logs syslog" should be checked to identify the exact errors that were reported. For example, if vmhost snapshot creation fails and "Mounting /dev/disk/by-label/efi_S failed - return code - 32" error message is seen, the following DMA errors were reported:

user@device> show vmhost logs kern.log | match "2025-03-26"
2025-03-26T01:26:15.557743+00:00 nge001 kernel: ata6.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
2025-03-26T01:26:15.557770+00:00 nge001 kernel: ata6.00: failed command: WRITE DMA
2025-03-26T01:26:15.557774+00:00 nge001 kernel: ata6.00: cmd ca/00:01:00:08:00/00:00:00:00:00/e0 tag 6 dma 512 out
2025-03-26T01:26:15.557777+00:00 nge001 kernel:         res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
2025-03-26T01:26:15.557780+00:00 nge001 kernel: ata6.00: status: { DRDY }
2025-03-26T01:26:15.557783+00:00 nge001 kernel: ata6: hard resetting link
2025-03-26T01:26:16.012739+00:00 nge001 kernel: ata6: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
2025-03-26T01:26:16.012760+00:00 nge001 kernel: ata6.00: configured for UDMA/133
2025-03-26T01:26:16.012764+00:00 nge001 kernel: ata6.00: device reported invalid CHS sector 0
2025-03-26T01:26:16.012767+00:00 nge001 kernel: ata6: EH complete
2025-03-26T01:26:46.273740+00:00 nge001 kernel: ata6.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
2025-03-26T01:26:46.273764+00:00 nge001 kernel: ata6.00: failed command: WRITE DMA
2025-03-26T01:26:46.273768+00:00 nge001 kernel: ata6.00: cmd ca/00:01:00:08:00/00:00:00:00:00/e0 tag 8 dma 512 out
2025-03-26T01:26:46.347314+00:00 nge001 kernel:         res 40/00:01:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
2025-03-26T01:26:46.347317+00:00 nge001 kernel: ata6.00: status: { DRDY }
2025-03-26T01:26:46.347319+00:00 nge001 kernel: ata6: hard resetting link
2025-03-26T01:26:46.750729+00:00 nge001 kernel: ata6: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
2025-03-26T01:26:46.751725+00:00 nge001 kernel: ata6.00: configured for UDMA/133
2025-03-26T01:26:46.751737+00:00 nge001 kernel: ata6: EH complete
2025-03-26T01:27:16.988744+00:00 nge001 kernel: ata6.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
2025-03-26T01:27:16.988767+00:00 nge001 kernel: ata6.00: failed command: WRITE DMA
2025-03-26T01:27:16.988771+00:00 nge001 kernel: ata6.00: cmd ca/00:01:00:08:00/00:00:00:00:00/e0 tag 12 dma 512 out
2025-03-26T01:27:16.988774+00:00 nge001 kernel:         res 40/00:01:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
2025-03-26T01:27:16.988778+00:00 nge001 kernel: ata6.00: status: { DRDY }
2025-03-26T01:27:16.988781+00:00 nge001 kernel: ata6: hard resetting link
2025-03-26T01:27:17.465858+00:00 nge001 kernel: ata6: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
2025-03-26T01:27:17.465872+00:00 nge001 kernel: ata6.00: configured for UDMA/133
2025-03-26T01:27:17.465875+00:00 nge001 kernel: ata6: EH complete

Recovery:

To resolve the issue, we may need to follow the below workaround during the MW time:

 

  1. If the device boots up again using the secondary disk, please run the command "request vmhost snapshot recovery partition" .

     
    > request vmhost snapshot recovery partition

warning: All existing data on the target media will be lost
Proceed ? [yes,no] (no) yes

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

  2. Reboot the affected RE using the command "request vmhost reboot".
  3. Suppose it failed to take the snapshot, then the exact errors need to be checked - "show vmhost logs kern.log" and "show vmhost logs syslog" commands.
  4. Please try to reboot RE again or perform CB offline/online, and check the exact errors (if any). If the errors remain the same, RE needs to be replaced.
  • request vmhost reboot
  • request chassis cb slot offline 1

 

Modification History

2025-03-26 : Formatting changes; added more diagnostic commands

2024-12-25 : Article Created