Creating a snapshot on a cluster

To create and mount a snapshot on a two-node cluster using cluster file system administrative interface commands.

To create a snapshot on a cluster file system

  1. To create a VxFS file system on a shared VxVM volume, type the following command:
    # mkfs -t vxfs /dev/vx/rdsk/cfsdg/vol1
    version 10 layout
    104857600 sectors, 52428800 blocks of size 1024, log size 
    16384 blocks unlimited inodes, largefiles not supported 
    52428800 data blocks, 52399152 free data blocks 1600 
    allocation units of 32768 blocks, 32768 data blocks
  2. To mount the file system on all nodes, type the following commands:
    # cfsmntadm add cfsdg vol1 /mnt1 all=cluster
    # cfsmount /mnt1

    The cfsmntadm command adds an entry to the cluster manager configuration, then the cfsmount command mounts the file system on all nodes.

  3. Add the snapshot on a previously created volume (snapvol in this example) to the cluster manager configuration. For example:
    # cfsmntadm add snapshot cfsdg snapvol /mnt1 /mnt1snap sys1=ro

    The snapshot of a cluster file system is accessible only on the node where it is created; the snapshot file system itself cannot be cluster mounted.

  4. Create and locally mount the snapshot file system on sys1, type the following command:
    # cfsmount /mnt1snap
  5. A snapped file system cannot be unmounted until all of its snapshots are unmounted. Unmount and destroy the snapshot before trying to unmount the snapped cluster file system, type the following command:
    # cfsumount /mnt1snap