Create a FlexCache volume


You can create a FlexCache volume in the same cluster for improving performance when accessing a hot object. If you have data centers in different locations, you can create FlexCache volumes on remote clusters for accelerating data access.

About this task

The FlexCache volume is always a FlexGroup volume, and not a FlexVol volume.

Starting with ONTAP 9.7, FlexGroup volumes are also supported at the origin of the FlexCache relationship.

  1. If the FlexCache volume to be created is in a different cluster, create a cluster peer relationship:

    1. On the destination cluster, create a peer relationship with the data protection source cluster:
      cluster peer create -generate-passphrase -offer-expiration MM/DD/YYYY HH:MM:SS|1…​7days|1…​168hours -peer-addrs peer_LIF_IPs -initial-allowed-vserver-peers svm_name,..|* -ipspace ipspace_name

      Starting with ONTAP 9.6, TLS encryption is enabled by default when creating a cluster peer relationship. TLS encryption is supported for the intercluster communication between the origin and FlexCache volumes. You can also disable TLS encryption for the cluster peer relationship, if required.

      cluster02::> cluster peer create -generate-passphrase -offer-expiration 2days -initial-allowed-vserver-peers *
                           Passphrase: UCa+6lRVICXeL/gq1WrK7ShR
                      Expiration Time: 6/7/2017 08:16:10 EST
        Initial Allowed Vserver Peers: *
                  Intercluster LIF IP:
                    Peer Cluster Name: Clus_7ShR (temporary generated)
      Warning: make a note of the passphrase - it cannot be displayed again.
    2. On the source cluster, authenticate the source cluster to the destination cluster:
      cluster peer create -peer-addrs peer_LIF_IPs -ipspace ipspace

      cluster01::> cluster peer create -peer-addrs,
      Notice: Use a generated passphrase or choose a passphrase of 8 or more characters.
              To ensure the authenticity of the peering relationship, use a phrase or sequence of characters that would be hard to guess.
      Enter the passphrase:
      Confirm the passphrase:
      Clusters cluster02 and cluster01 are peered.
  2. If the FlexCache volume is in a different SVM than that of the origin volume, create an SVM peer relationship with flexcache as the application:

    1. If the SVM is in a different cluster, create an SVM permission for the peering SVMs:
      vserver peer permission create -peer-cluster cluster_name -vserver svm-name -applications flexcache

      The following example illustrates how to create an SVM peer permission that applies for all of the local SVMs:

      cluster1::> vserver peer permission create -peer-cluster cluster2 -vserver "*" -applications flexcache
      Warning: This Vserver peer permission applies to all local Vservers. After that no explict
      "vserver peer accept" command required for Vserver peer relationship creation request
      from peer cluster "cluster2" with any of the local Vservers. Do you want to continue? {y|n}: y
    2. Create the SVM peer relationship:
      vserver peer create -vserver local_SVM -peer-vserver remote_SVM -peer cluster cluster_name -applications flexcache

  3. Create a FlexCache volume:

    volume flexcache create -vserver cache_svm -volume cache_vol_name -auto-provision-as flexgroup -size vol_size -origin-vserver origin_svm -origin-volume origin_vol_name

    The following example creates a FlexCache volume and automatically selects existing aggregates for provisioning:

    cluster1::> volume flexcache create -vserver vs_1 -volume fc1 -auto-provision-as flexgroup -origin-volume vol_1 -size 160MB -origin-vserver vs_1
    [Job 443] Job succeeded: Successful

    The following example creates a FlexCache volume and sets the junction path:

    cluster1::> flexcache create -vserver vs34 -volume fc4 -aggr-list aggr34,aggr43 -origin-volume origin1 -size 400m -junction-path /fc4
    [Job 903] Job succeeded: Successful
  4. Verify the FlexCache relationship from the FlexCache volume and the origin volume.

    1. View the FlexCache relationship in the cluster:
      volume flexcache show

      cluster1::> volume flexcache show
      Vserver Volume      Size       Origin-Vserver Origin-Volume Origin-Cluster
      ------- ----------- ---------- -------------- ------------- --------------
      vs_1    fc1         160MB      vs_1           vol_1           cluster1
    2. View all of the FlexCache relationships in the origin cluster:
      volume flexcache origin show-caches

      cluster::> volume flexcache origin show-caches
      Origin-Vserver Origin-Volume   Cache-Vserver    Cache-Volume   Cache-Cluster
      -------------- --------------- ---------------  -------------- ---------------
      vs0            ovol1           vs1              cfg1           clusA
      vs0            ovol1           vs2              cfg2           clusB
      vs_1           vol_1           vs_1             fc1            cluster1


The FlexCache volume is successfully created. Clients can mount the volume by using the junction path of the FlexCache volume.

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