Description of problem:

Error seen when monitoring gluster volume status detail - resulting in monitoring of capacity and size not working for some volumes.

This is seen when the gluster output does not contain the size related fields:
<cliOutput>
  <opRet>0</opRet>
  <opErrno>0</opErrno>
  <opErrstr/>
  <volStatus>
    <volumes>
      <volume>
        <volName>vmstore</volName>
        <nodeCount>3</nodeCount>
        <node>
          <hostname>10.70.37.28</hostname>
          <path>/gluster_bricks/vmstore/vmstore</path>
          <peerid>61924995-48fb-487b-bc8c-5dba9b041dc1</peerid>
          <status>1</status>
          <port>49154</port>
          <ports>
            <tcp>49154</tcp>
            <rdma>N/A</rdma>
          </ports>
          <pid>3531</pid>
          <sizeTotal>9661531029504</sizeTotal>
          <sizeFree>9658771755008</sizeFree>
          <device>/dev/mapper/gluster_vg_sdd-gluster_lv_vmstore</device>
          <blockSize>4096</blockSize>
          <mntOptions>rw,seclabel,noatime,nodiratime,attr2,inode64,sunit=512,swidth=2048,noquota</mntOptions>
          <fsName>xfs</fsName>
          <inodeSize>xfs</inodeSize>
          <inodesTotal>943717568</inodesTotal>
          <inodesFree>943715561</inodesFree>
        </node>
        <node>
          <hostname>10.70.37.29</hostname>
          <path>/gluster_bricks/vmstore/vmstore</path>
          <peerid>bd08ff35-c56c-4d6c-aff3-58b9eaaf1f55</peerid>
          <status>1</status>
          <port>49153</port>
          <ports>
            <tcp>49153</tcp>
            <rdma>N/A</rdma>
          </ports>
          <pid>20266</pid>
        </node>
        <node>
          <hostname>10.70.37.30</hostname>
          <path>/gluster_bricks/vmstore/vmstore</path>
          <peerid>a03dfa62-5766-4431-a0be-e46b81d2e7af</peerid>
          <status>0</status>
          <port>N/A</port>
          <ports>
            <tcp>N/A</tcp>
            <rdma>N/A</rdma>
          </ports>
          <pid>-1</pid>
        </node>
      </volume>
    </volumes>
  </volStatus>
</cliOutput>


Version-Release number of selected component (if applicable):


How reproducible:
Sometimes

Steps to Reproduce:
Not sure under what conditions gluster fails to report these.