Search for:

Available article translations:

How to troubleshoot kernel panic in virtual machine

  • Parallels Cloud Server 6.0
  • Parallels Server


Stop the virtual machine and add a COM port as shown in the picture below:




When starting the VM, enter the boot loader menu (by typing "E" when the GRUB window appears):


Select the line with the kernel options and hit "E" once again:


Append the string with the debug console=<ttySN>,115200 console=tty options and hit Enter.

NOTE: <ttySN> represents a COM port name with its number. If you have the only serial port attached to the virtual machine, then it would be ttyS0; if there are several, then you should be able to find it by issuing this command:

# prlctl list –i VMNAME | grep serial

For example:

[root@hostserver ~]# prlctl list -i 'CentOS Linux' | grep serial    
serial0 (+) socket='/tmp/com_1'
serial1 (+) output='/vz/vmprivate/CentOS Linux.pvm/serial2.txt'

So, in this example, it would be ttyS1:


The resulting window should look like this:


Now hit "b" to boot the selected kernel, and in the meantime, check the output file that was specified from the host server:

[root@hostserver ~]# tail –f '/vz/vmprivate/CentOS 5.5 x64 Serial Console.pvm/serial2.txt'
Linux version 2.6.18-194.el5 ( (gcc version 4.1.2 20080704 (Red Ha
t 4.1.2-48)) #1 SMP Fri Apr 2 14:58:14 EDT 2010
Command line: ro root=LABEL=/1 debug console=ttyS1,115200 console=tty
BIOS-provided physical RAM map:
BIOS-e820: 0000000000010000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000dc000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000007fff0000 (usable)
BIOS-e820: 000000007fff0000 - 000000007ffff000 (ACPI data)
BIOS-e820: 000000007ffff000 - 0000000080000000 (ACPI NVS)
BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
BIOS-e820: 00000000ffc00000 - 0000000100000000 (reserved)
DMI 2.3 present.
ACPI: RSDP (v002 PRLS                                  ) @ 0x00000000000e8000
ACPI: XSDT (v001 PRLS   PRLS_OEM 0x00000001 INTL 0x20051216) @ 0x000000007fff0040
ACPI: FADT (v003 PRLS   PRLS_OEM 0x00000001 INTL 0x20051216) @ 0x000000007fff0100
ACPI: MADT (v001 PRLS   PRLS_OEM 0x00000001 INTL 0x20051216) @ 0x000000007fff0240
ACPI: DSDT (v002 PRLS   PRLSACPI 0x00001001 INTL 0x20051216) @ 0x0000000000000000
No NUMA configuration found
Faking a node at 0000000000000000-000000007fff0000
Bootmem setup node 0 0000000000000000-000000007fff0000
Memory for crash kernel (0x0 to 0x0) notwithin permissible range
disabling kdump
On node 0 totalpages: 515693

Thus, when the kernel panic message appears, you will have the exact text output that can be used for searching in RedHat bugzilla and forums.

When submitting a request to Parallels Technical Support, please have the output file attached.

Additional Information

Also see this article about configuring the serial console output for MacOS-based VMs:

  • 113113 How to troubleshoot kernel panic in MacOS-based virtual machine

Search words:

kernel panic


ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen


serial console

com port


ca05eaf5b843fbd53589c90d7228a6df 2897d76d56d2010f4e3a28f864d69223 bf1c3a170005eae151f49ba2720abde9 3d9560cc94370f9e1bd9256d230e5ee8

Was this article helpful?
Tell us how we may improve it.
Yes No
Desktop Virtualization
- Parallels Desktop 9 for Mac
- Parallels Transporter
- Parallels Desktop Switch to Mac Edition
- Parallels Desktop for Mac Enterprise Edition
- Parallels Management-Mac for Microsoft SCCM
Server Virtualization
- Parallels Cloud Server
- Parallels Containers for Windows 6.0 Beta
- Parallels Virtuozzo Containers
- Parallels Automation
- Parallels Automation for Cloud Infrastructure
- Parallels Business Automation Standard
- Parallels Virtual Automation
- Parallels Plesk Panel Suite
- Web Presence Builder
- Parallels Plesk Automation
- Parallels Small Business Panel
- Value-added Services for Hosters
- Parallels Partner Storefront
Services & Resources
- Cloud Acceleration Services
- Professional Services
- Support Services
- Training & Certification