drmdump directory using a high amount of disk space on VCSA 7.x instances

Products

• VMware vCenter Server

Issue/Introduction

• Investigating the cause of high disk usage in /storage/log might show that the ../vpxd/drmdump folder is a large contributor to the space usage.

Environment

VMware vCenter Server 7.0.x

Cause

The drmdump directory is where DRS logs its calculations for load balancing and placement recommendations. 
  Each cluster is contained in a sub-directiory named after its moID.  Compute clusters are named domain-c* while storage clusters are named group-p*

Each log is rotated and compressed when it reaches 21MB in size as documented here - https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/techpaper/performance/drs-dump-insight-user-guide-perf.pdf

DRS 2.0: vSphere version 7.0 and later
Each drmdump file contains actions proposed and taken by DRS for a variable time interval limited on a file size of 21 MB.

In previous version of DRS, each cluster folder was also limited to a 20MB size by default but this is no longer the case in 7.0.

Resolution

Workaround:

To manage age the size limitation of these directories we can add the following settings to the vpxd.cfg.

  <drs>
      <plmtDump>
        <logSize>5242880</logSize>
        <numFiles>15</numFiles>
    </plmtDump>
  </drs>

 

**NOTE this will require the vCenter Service be restarted**

1.  SSH to the VCSA system and login as root
2. Backup the existing vpxd.cfg file 

             cp /etc/vmware-vpx/vpxd.cfg /etc/vmware-vpx/vpxd.cfg.bak

     3. Stop the vCenter service
          
             service-control --stop vpxd

      4. Edit the /etc/vmware-vpx/vpxd.cfg with vi
      5. Place the following options with the desired values between the <drs></drs> section

            <plmtDump>
                <logSize>5242880</logSize>                <---- Size in bytes
                <numFiles>15</numFiles>                      <---- number of log files per directory
            </plmtDump>
     
      6.  Save the file
      7.  Start vCenter server

           service-control --start vpxd