Testing I/O performance for IBM® Cloud Pak for Data

To ensure that the storage partition for Cloud Pak for Data has good disk I/O performance, run the disk latency test and the disk throughput test.

About this task

Run the following tests on the mount path of PVC for user-home-pvc and database-storage-wdp-couchdb to evaluate storage performance for the Cloud Pak for Data platform level:

Disk latency test
dd if=/dev/zero of=/PVC_mount_path/testfile bs=4096 count=1000 oflag=dsync

The value must be better or comparable to: 4096000 bytes (4.1 MB, 3.9 MiB) copied, 1.5625 s, 2.5 MB/s

Disk throughput test
dd if=/dev/zero of=/PVC_mount_path/testfile bs=1G count=1 oflag=dsync

The value must be better or comparable to: 1073741824 bytes (1.1 GB) copied, 5.14444 s, 209 MB/s

Procedure

On the PVC for user-home-pvc, complete the following steps:

  1. Sign in to the infrastructure node.
  2. Get the PV name for user-home-pvc: 
    oc get pvc | grep user-home-pvc
    In this example output, the PV name is pvc-8ff016d9-ab1e-48c1-93e7-06711132f73f:
    user-home-pvc  Bound     pvc-8ff016d9-ab1e-48c1-93e7-06711132f73f    10Gi       RWX            ocs-storagecluster-cephfs   4d
  3. Find the compute node that has the PVC mount path: 
    oc get pod -o wide | grep ibm-nginx
    Use the compute node from the first line of the output. In this example output, the compute note is worker0.abc.com:
    ibm-nginx-59c44d5c88-dx9s9 1/1 Running 0 4d 10.254.20.26  worker0.abc.com  <none> <none>
ibm-nginx-59c44d5c88-gn89t 1/1 Running 0 4d 10.254.28.33 worker4.abc.com <none> <none>
ibm-nginx-59c44d5c88-lj4f4 1/1 Running 0 4d 10.254.12.27 worker2.abc.com <none> <none>
  4. SSH to the compute node:
    OpenShift® 3.11 example:
    ssh worker0.abc.com
    OpenShift 4.3 example:
    ssh core@worker0.abc.com
  5. Find the PVC mount path: 
    sudo -i mount | grep PV_name
    Example:
    sudo -i mount | grep pvc-8ff016d9-ab1e-48c1-93e7-06711132f73f
    Use the mount path from the first line of output. In this example output, the mount path is /var/lib/kubelet/plugins/kubernetes.io/csi/pv/pvc-8ff016d9-ab1e-48c1-93e7-06711132f73f/globalmount:

    9.87.654.321:6789:/volumes/csi/csi-vol-0db42915-810a-11ea-bdda-0a580afe000f/07f06c31-5859-424d-b2a7-d7b07e93c778 on  /var/lib/kubelet/plugins/kubernetes.io/csi/pv/pvc-8ff016d9-ab1e-48c1-93e7-06711132f73f/globalmount  type ceph (rw,relatime,name=csi-cephfs-node,secret=<hidden>,acl,mds_namespace=cephfs) ...

  6. Run DD tests on the PVC mount path.
    Example:
    dd if=/dev/zero of=/var/lib/kubelet/plugins/kubernetes.io/csi/pv/pvc-8ff016d9-ab1e-48c1-93e7-06711132f73f/globalmount/testfile bs=4096 count=1000 oflag=dsync
dd if=/dev/zero of=/var/lib/kubelet/plugins/kubernetes.io/csi/pv/pvc-8ff016d9-ab1e-48c1-93e7-06711132f73f/globalmount/testfile bs=1G count=1 oflag=dsync
  7. After the DD tests, remove the testfile from the pvc mount path.

On the PVC for database-storage-wdp-couchdb, complete the same steps:

  1. Sign in to the infrastructure node.
  2. Get the PV name for database-storage-wdp-couchdb: 
    oc get pvc | grep database-storage-wdp-couchdb-0
    In this example output, the PV name is pvc-0a219fac-7eda-11ea-8aa3-0686c9fc25ca:
    database-storage-wdp-couchdb-0     Bound      pvc-0a219fac-7eda-11ea-8aa3-0686c9fc25ca    30Gi       RWO            portworx-couchdb-sc      7d
  3. Find the compute node that has the PVC mount path: 
    oc get pod -o wide | grep couchdb-0
    Use the compute node from the first line of the output. In this example output, the compute note is cp4dperf0dworker-01.abc.com:
    wdp-couchdb-0      1/1       Running     0          5d        172.16.13.251    cp4dperf0dworker-01.abc.com    <none>
  4. SSH to the compute node:
    OpenShift 3.11 example:
    ssh cp4dperf0dworker-01.abc.com
    OpenShift 4.3 example:
    ssh cp4dperf0dworker-01.abc.com
  5. Find the PVC mount path: 
    sudo -i mount | grep PV_name
    Example:
    sudo -i mount | grep pvc-0a219fac-7eda-11ea-8aa3-0686c9fc25ca
    Use the mount path from the first line of output. In this example output, the mount path is /var/lib/origin/openshift.local.volumes/pods/4ac82de0-8042-11ea-8aa3-0686c9fc25ca/volumes/kubernetes.io~portworx-volume/pvc-0a219fac-7eda-11ea-8aa3-0686c9fc25ca:

    /dev/pxd/pxd1016725635306676869 on  /var/lib/origin/openshift.local.volumes/pods/4ac82de0-8042-11ea-8aa3-0686c9fc25ca/volumes/kubernetes.io~portworx-volume/pvc-0a219fac-7eda-11ea-8aa3-0686c9fc25ca  type ext4 (rw,relatime,seclabel,discard,data=ordered)

  6. Run DD tests on the PVC mount path.
    Example:
    dd if=/dev/zero of=/var/lib/origin/openshift.local.volumes/pods/4ac82de0-8042-11ea-8aa3-0686c9fc25ca/volumes/kubernetes.io~portworx-volume/pvc-0a219fac-7eda-11ea-8aa3-0686c9fc25ca/testfile bs=4096 count=1000 oflag=dsync
dd if=/dev/zero of=/var/lib/origin/openshift.local.volumes/pods/4ac82de0-8042-11ea-8aa3-0686c9fc25ca/volumes/kubernetes.io~portworx-volume/pvc-0a219fac-7eda-11ea-8aa3-0686c9fc25ca/testfile bs=1G count=1 oflag=dsync
  7. After the DD tests, remove the testfile from the pvc mount path.