Chapter 6. Maintaining and Administrating Red Hat Enterprise Virtualization Hypervisors

This chapter covers administration and maintenance tasks for Red Hat Enterprise Virtualization Hypervisors.

6.1. Enabling kdumps

RHEV Hypervisor hosts generate a kernel dump (a kdump file) in the event of a system failure. These kdump files are essential for debugging and support.
All kdump files are placed on the /data partition of the storage on the RHEV Hypervisor host. When installing a RHEV Hypervisor host, ensure there is sufficient persistent storage space for kdump files. The size of the kdump file is proportional to the amount of RAM installed on the host. For a system with 32GB of RAM, a Hypervisor requires a /data partition of at least 32GB plus additional space for RHEV specific data (approximately 512MB).
The kdump file can be transferred off the RHEV Hypervisor host once the host is rebooted and is running properly. To transfer the kdump file, use the following procedure.

SSH for Windows systems

There is an Open Source SSH client for Windows systems called PuTTY. Download the client from the PuTTY homepage: http://www.chiark.greenend.org.uk/~sgtatham/putty/. Using PuTTY to transfer files is not supported by this guide although many of the steps will remain the same.
  1. Access a Linux, UNIX, or similar operating systems with SSH and the scp command installed. The scp command has the following format:
    scp source-user@source_IP_OR_hostname:/path/to/files destination-user@destination_IP_OR_hostname:/path/to/destination
  2. This example copies all kdump files to the /tmp/RHEVkdumps directory on the local system. Use the administrator (root) username and password configured during RHEV Hypervisor installation. Replace the example hostname, rhevh.example.com, with a valid IP address or hostname for the RHEV Hypervisor.
    $ scp -r root@rhevh.example.com:'/data/core/*' /tmp/RHEVkdumps
    
  3. Once this procedure completes you can delete all the original kdump files on the Hypervisor. Log into the Hypervisor as root and execute the following.
    # rm -rf /data/core/*
    
The kdump file is now removed and available on the other host for support and debugging.