Sun Cluster Software Installation Guide for Solaris OS

ProcedureHow to Mirror the Root (/) File System

Use this procedure to mirror the root (/) file system.

Note –

If the global-devices namespace is on a lofi-created file, this procedure includes the mirroring of the global-devices namespace.

  1. Become superuser.

  2. Place the root slice in a single-slice (one-way) concatenation.

    Specify the physical disk name of the root-disk slice (cNtXdYsZ).

    phys-schost# metainit -f submirror1 1 1 root-disk-slice
  3. Create a second concatenation.

    phys-schost# metainit submirror2 1 1 submirror-disk-slice
  4. Create a one-way mirror with one submirror.

    phys-schost# metainit mirror -m submirror1

    Note –

    If the device is a local device to be used to mount a global-devices file system, /global/.devices/node@nodeid, the volume name for the mirror must be unique throughout the cluster.

  5. Set up the system files for the root (/) directory.

    phys-schost# metaroot mirror

    This command edits the /etc/vfstab and /etc/system files so the system can be booted with the root (/) file system on a metadevice or volume. For more information, see the metaroot(1M) man page.

  6. Flush all file systems.

    phys-schost# lockfs -fa

    This command flushes all transactions out of the log and writes the transactions to the master file system on all mounted UFS file systems. For more information, see the lockfs(1M) man page.

  7. Move any resource groups or device groups from the node.

    phys-schost# clnode evacuate from-node

    Specifies the name of the node from which to evacuate resource or device groups.

  8. Reboot the node.

    This command remounts the newly mirrored root (/) file system.

    phys-schost# shutdown -g0 -y -i6
  9. Attach the second submirror to the mirror.

    phys-schost# metattach mirror submirror2

    See the metattach(1M) man page for more information.

  10. If the disk that is used to mirror the root disk is physically connected to more than one node (multihosted), disable fencing for that disk.

    Disabling fencing for the device prevents unintentional fencing of a node from its boot device if the boot device is connected to multiple nodes.

    phys-schost# cldevice set -p default_fencing=nofencing submirror-disk

    Specifies a device property.


    Disables fencing for the specified device.

    For more information about the default_fencing property, see the cldevice(1CL) man page.

  11. Record the alternate boot path for possible future use.

    If the primary boot device fails, you can then boot from this alternate boot device. See Special Considerations for Mirroring root (/) in Solaris Volume Manager Administration Guide or Creating a RAID-1 Volume in Solaris Volume Manager Administration Guide for more information about alternate boot devices.

    phys-schost# ls -l /dev/rdsk/root-disk-slice
  12. Repeat Step 1 through Step 11 on each remaining node of the cluster.

    Ensure that each volume name for a mirror on which a global-devices file system, /global/.devices/node@nodeid, is to be mounted is unique throughout the cluster.

Example 4–2 Mirroring the Root (/) File System

The following example shows the creation of mirror d0 on the node phys-schost-1, which consists of submirror d10 on partition c0t0d0s0 and submirror d20 on partition c2t2d0s0. Device c2t2d0 is a multihost disk, so fencing is disabled. The example also displays the alternate boot path for recording.

phys-schost# metainit -f d10 1 1 c0t0d0s0
d11: Concat/Stripe is setup
phys-schost# metainit d20 1 1 c2t2d0s0
d12: Concat/Stripe is setup
phys-schost# metainit d0 -m d10
d10: Mirror is setup
phys-schost# metaroot d0
phys-schost# lockfs -fa
phys-schost# clnode evacuate phys-schost-1
phys-schost# shutdown -g0 -y -i6
phys-schost# metattach d0 d20
d0: Submirror d20 is attachedphys-schost# cldevice set -p default_fencing=nofencing c2t2d0
phys-schost# ls -l /dev/rdsk/c2t2d0s0
lrwxrwxrwx  1 root     root          57 Apr 25 20:11 /dev/rdsk/c2t2d0s0 
–> ../../devices/node@1/pci@1f,0/pci@1/scsi@3,1/disk@2,0:a,raw

Next Steps

To mirror the global devices namespace, /global/.devices/node@nodeid, go to How to Mirror the Global Devices Namespace.

To mirror file systems than cannot be unmounted, go to How to Mirror File Systems Other Than Root (/) That Cannot Be Unmounted.

To mirror user-defined file systems, go to How to Mirror File Systems That Can Be Unmounted.

Otherwise, go to Creating Disk Sets in a Cluster to create a disk set.


Some of the steps in this mirroring procedure might cause an error message similar to metainit: dg-schost-1: d1s0: not a metadevice. Such an error message is harmless and can be ignored.