Recreating a core dump file in OSDATA

Products

• VMware vSphere ESXi

Issue/Introduction

ESXi stores its core dump files on the OSDATA partition by default.

This article provides steps for recreating a core dump file in OSDATA when you are unable to generate a core dump file due to an error such as "Unable to copy the dump file: Error: vmkernel dump version mismatch!".

For steps to specify VMFS as the destination for generating core dump files instead of OSDATA, refer to the article "Configuring ESXi coredump to file instead of partition."

Environment

VMware vSphere ESXi 8.x
VMware vSphere ESXi 7.x

Resolution

Recreating the core dump file on OSDATA requires deleting the existing core dump file.

 

The procedure for removing an existing dump file and creating a new one is as follows:

1. Log in to the ESXi host using SSH.
   
   
2. Confirm the UUID of the OSDATA.
   

   esxcli storage filesystem list 

   Example output : 

   # esxcli storage filesystem list
Mount Point                                        Volume Name                                 UUID                                 Mounted  Type            Size         Free
-------------------------------------------------  ------------------------------------------  -----------------------------------  -------  ------  ------------  -----------
/vmfs/volumes/6752####-########-####-#####6aab69c  iscsi-101                                   6752####-########-####-#####6aab69c     true  VMFS-6  139318001664  48624566272
/vmfs/volumes/6736####-########-####-#####6aab69c  OSDATA-6736####-########-####-#####6aab69c  6736####-########-####-#####6aab69c     true  VMFSOS   25501368320  22177382400
/vmfs/volumes/4c40####-########-####-#####eb6dae2  BOOTBANK1                                   4c40####-########-####-#####eb6dae2     true  vfat      4293591040   4003332096
/vmfs/volumes/2258####-########-####-#####608d64f  BOOTBANK2                                   2258####-########-####-#####608d64f     true  vfat      4293591040   3989766144

   In this example, 6736####-########-####-#####6aab69c is the OSDATA UUID.

3. Check the existing core dump file on OSDATA.
   
   esxcli system coredump file list
   
   

   Example output:

   # esxcli system coredump file list
Path                                                                                                     Active  Configured        Size
-------------------------------------------------------------------------------------------------------  ------  ----------  ----------
/vmfs/volumes/6736####-########-####-#####6aab69c/vmkdump/50EC####-####-####-####-#####B582956.dumpfile    true        true  1263534080

   The red part in the Path matches the UUID in OSDATA

4. Deactivate the existing core dump file.
   

   esxcfg-dumppart -d

   After executing the command, the coredump file status will change to Active "false" and Configured "true".

   Example output:

   # esxcfg-dumppart -d
Dump file deactivated.

   # esxcli system coredump file list
Path                                                                                                     Active  Configured        Size
-------------------------------------------------------------------------------------------------------  ------  ----------  ----------
/vmfs/volumes/6736####-########-####-#####6aab69c/vmkdump/50EC####-####-####-####-#####582956.dumpfile   false        true  1263534080

   
   
   
5. Remove the existing Configured core dump file on OSDATA.
   

   esxcli system coredump file remove --force

   After executing this command, coredump file will no longer be output by "esxcli system coredump file list" command.

6. Create a new core dump file in OSDATA and check the path of the created file.
   

   esxcli system coredump file add -d <OSDATA UUID>
esxcli system coredump file list

   Example output:

   # esxcli system coredump file add -d 6736####-########-####-#####6aab69c
 
# esxcli system coredump file list
Path                                                                                                     Active  Configured        Size
-------------------------------------------------------------------------------------------------------  ------  ----------  ----------
/vmfs/volumes/6736####-########-####-#####6aab69c/vmkdump/50EC####-####-####-####-#####B582956.dumpfile   false       false  1263534080

   In this example, the path value is "/vmfs/volumes/6736####-########-####-#####6aab69c/vmkdump/50EC####-####-####-####-#####B582956.dumpfile".
   
   
   
7. Activate the created core dump file.
   

   esxcli system coredump file set -p <Path of the core dump file confirmed in the previous step>

   If the coredump file is successfully activated, the newly created dumpfile will be marked as Active "true" and Configured "true".
   
   Example output:

   # esxcli system coredump file set -p /vmfs/volumes/6736####-########-####-#####6aab69c/vmkdump/50EC####-####-####-####-#####B582956.dumpfile

   # esxcli system coredump file list
Path                                                                                                     Active  Configured        Size
-------------------------------------------------------------------------------------------------------  ------  ----------  ----------
/vmfs/volumes/6736####-########-####-#####6aab69c/vmkdump/50EC####-####-####-####-#####B582956.dumpfile    true        true  1263534080

 

 

Additional Information

Collecting a livedump to the active dumpfile and outputting it to a zdump file can be performed with the following commands.

 

Collect livedump to the active dumpfile: 

esxcli --plugin-dir /usr/lib/vmware/esxcli/int/ debug livedump perform

 

Output the livedump to a zdump file: 

esxcfg-dumppart --file --copy --devname active

 

For details on collecting a livedump and outputting to a zdump file, please refer to: Generating a VMkernel zdump manually from a dump file in ESXi host.