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Sun Cluster 3.1 With Network-Attached Storage Devices Manual for Solaris OS

Chapter 1 Installing and Maintaining Network Appliance Network-Attached Storage Devices in a Sun Cluster Environment

This chapter contains procedures about installing and maintaining Network Appliance network-attached storage (NAS) devices in a SunTM Cluster environment. Before you perform any of the procedures in this chapter, read the entire procedure. If you are not reading an online version of this document, have the books listed in Related Books available.

This chapter contains the following procedures:

For conceptual information about multihost storage devices, see the Sun Cluster Concepts Guide for Solaris OS.

Requirements, Recommendations, and Restrictions for Network Appliance NAS Devices

This section includes only restrictions and requirements that have a direct impact on the procedures in this chapter. For general support information, contact your Sun service provider.

Requirements for Network Appliance NAS Devices

Requirements When Configuring All NAS Devices

When you use a Network Appliance NAS device, the following are always required:

Requirements When Configuring NAS Devices for Use With Oracle Real Application Clusters

When setting up your NAS device:

Requirements When Configuring NAS Devices as Quorum Devices

When you use a NAS device as a quorum device, the following are required:

Recommendations for Network Appliance NAS Device

It is strongly recommended that you use a NetApp clustered filer. Clustered filers provide high availability with respect to the filer data and do not constitute a single point of failure in the cluster.

It is strongly recommended that you use the network time protocol (NTP) to synchronize time on the cluster nodes and the NAS device. Refer to your Network Appliance documentation for instructions about how to configure NTP on the NAS device. Select at least one NTP server for the NAS device that also serves the cluster nodes.

Restrictions for Network Appliance NAS Devices

When configuring a NAS device as a quorum device, you can only add the quorum device when all cluster nodes are operational and communicating with the NAS device.

Installing a Network Appliance NAS Device in a Sun Cluster Environment

ProcedureHow to Install a Network Appliance NAS Device in a Cluster

Before You Begin

This procedure relies on the following assumptions:

  1. Set up the NAS device.

    You can set up the device at any point in your cluster installation. Follow the instructions in your device's documentation. See Related Third-Party Web Site References for a list of related device documentation.

    When setting up your NAS device, follow the standards that are described in Requirements, Recommendations, and Restrictions for Network Appliance NAS Devices.

  2. Install the NAS-support software package NTAPclnas on each node in the cluster.

    Perform this step after you have installed the Solaris OS and the Sun Cluster software.

    If this is the first NAS device in your cluster, or if you need to upgrade the NAS-support software package, perform this step. See Related Third-Party Web Site References for instructions about downloading and installing this software.

  3. On each cluster node, add the NAS device name to the /etc/inet/hosts file.

    Add a hostname-to-address mapping for the device in the /etc/inet/hosts file on all cluster nodes. For example:


    netapp-123 192.168.11.123

  4. On each cluster node, add the device netmasks to the /etc/inet/netmasks file.

    Add an entry to the /etc/inet/netmasks file for the subnet the filer is on. For example:


    192.168.11.0 255.255.255.0

  5. Verify that the hosts and netmasks entries in /etc/nsswitch.conf file on all cluster nodes have files appearing before nis and dns. If they are not, edit the corresponding line in /etc/nsswitch.conf by moving files before nis and dns.

  6. Add the NAS device to the cluster.

    1. From any cluster node, add the device by using the scnas command.


      # scnas -a -h myfiler -t netapp -o userid=root
      -a

      Add the device to cluster configuration.

      -h

      Is the name of the NAS device you are adding.

      -o userid

      Is the HTTP administrator login for the NAS device.

    2. At the prompt, type the HTTP administrator password.

    3. Confirm that the device has been added to the cluster.


      # scnas -p

    For more information about the scnas command, see the scnas(1M) man page.

  7. Add the NAS directories to the cluster.

    Follow the directions in How to Add Network Appliance NAS Directories to a Cluster.

  8. (Optional) Configure a LUN on the NAS device as a quorum device.

    See How to Add a Network Appliance Network-Attached Storage (NAS) Quorum Device in Sun Cluster System Administration Guide for Solaris OS for instructions for configuring a NAS quorum device.

Maintaining a Network Appliance NAS Device in a Sun Cluster Environment

This section contains procedures about maintaining NAS devices that are attached to a cluster. If a device's maintenance procedure might jeopardize the device's availability to the cluster, you must always perform the steps in How to Prepare the Cluster for Network Appliance NAS Device Maintenance before performing the maintenance procedure. After performing the maintenance procedure, perform the steps in How to Restore Cluster Configuration After Network Appliance NAS Device Maintenance to return the cluster to its original configuration.

Network Appliance NAS Device Procedures That Do Not Require Cluster Preparation

The following Network Appliance clustered-filer procedures can be performed without affecting the filer's availability.

Caution – Caution –

When performing any maintenance procedure other than those listed, perform the steps in How to Prepare the Cluster for Network Appliance NAS Device Maintenance before the maintenance procedure. Perform the steps in How to Restore Cluster Configuration After Network Appliance NAS Device Maintenance after performing the maintenance procedure.

If you fail to prepare the cluster, you can experience loss of cluster availability. If the cluster loses access to the NAS device's directories, your cluster applications will experience I/O errors, might not be able to fail over correctly, and might fail. If your cluster experiences this kind of failure, you must reboot the entire cluster (booting NAS device before the cluster nodes). If your cluster loses access to a NAS quorum device, and then a node fails, the entire cluster can become unavailable. In this case, you must either reboot the entire cluster (booting NAS device before the cluster nodes) or remove the quorum device and configure it again.

ProcedureHow to Prepare the Cluster for Network Appliance NAS Device Maintenance

Follow the instructions in this procedure whenever the NAS device maintenance you are performing might affect the device's availability to the cluster nodes.

  1. Stop I/O to the NAS device.

  2. On each cluster node, unmount the NAS device directories.

  3. Determine whether a LUN on this NAS device is a quorum device. 


    # scstat -q

    • If no, you are finished with this procedure.

    • If a LUN is a quorum device, perform the following steps:

      1. If your cluster uses other shared storage devices, select and configure another quorum device.

      2. Remove this quorum device.

        See Chapter 5, Administering Quorum, in Sun Cluster System Administration Guide for Solaris OS for instructions about adding and removing quorum devices.

        Note –

        If your cluster requires a quorum device (for example, a two-node cluster) and you are maintaining the only shared storage device in the cluster, your cluster is in a vulnerable state throughout the maintenance procedure. Loss of a single node during the procedure causes the other node to panic and your entire cluster becomes unavailable. Limit the amount of time for performing such procedures. To protect your cluster against such vulnerability, add a shared storage device to the cluster.

ProcedureHow to Restore Cluster Configuration After Network Appliance NAS Device Maintenance

Follow the instructions in this procedure after performing any NAS device maintenance that might affect the device's availability to the cluster nodes.

  1. Mount the NAS directories.

  2. Determine whether you want an iSCSI LUN on this NAS device to be a quorum device.

  3. Restore I/O to the NAS device.

ProcedureHow to Remove a Network Appliance NAS Device From a Cluster

Before You Begin

This procedure relies on the following assumptions:

Note –

When you remove the device from cluster configuration, the data on the device is not available to the cluster. Ensure that other shared storage in the cluster can continue to serve the data when the NAS device is removed

  1. From any cluster node, remove the device by using the scnas command. 


    # scnas -r -h myfiler
    -r

    Remove the device from cluster configuration

    -h

    Is the name of the NAS device you are removing

    For more information about the scnas command, see the scnas(1M) man page.

  2. Confirm that the device has been removed from the cluster.


    # scnas -p

ProcedureHow to Add Network Appliance NAS Directories to a Cluster

Before You Begin

The procedure relies on the following assumptions:

  1. From any cluster node, add the directories by using the scnasdir command. 


    # scnasdir -a -h myfiler -d /vol/DB1 -d /vol/DB2
    -a

    Add the directory or directories to cluster configuration.

    -h

    Is the name of the NAS device whose directories you are adding.

    -d

    Is the directory to add. Use this option once for each directory you are adding. This value must match the name of one of the directories exported by the NAS device.

    For more information about the scnasdir command, see the scnasdir(1M) man page.

  2. Confirm that the directories have been added. 


    # scnasdir -p

  3. If you do not use the automounter, mount the directories by performing the following steps:

    1. On each node in the cluster, create a mount-point directory for each NAS directory that you added.


      # mkdir -p /path-to-mountpoint
      path-to-mountpoint

      Name of the directory on which to mount the directory

    2. On each node in the cluster, add an entry to the /etc/vfstab file for the mount point.

      If you are using your NAS device for Oracle Real Application Clusters database files, set the following mount options:

      • forcedirectio

      • noac

      • proto=tcp

      When mounting NAS directories, select the mount options appropriate to your cluster applications. Mount the directories on each node that will access the directories. Sun Cluster places no additional restrictions or requirements on the options that you use.

ProcedureHow to Remove Network Appliance NAS Directories From a Cluster

Before You Begin

This procedure assumes that your cluster is operational.

Note –

When you remove the device directories, the data on those directories is not available to the cluster. Ensure that other device directories or shared storage in the cluster can continue to serve the data when these directories have been removed.

  1. If you are using hard mounts rather than the automounter, unmount the NAS directories:

    1. On each node in the cluster, unmount the directories you are removing.


      # umount /mount-point

    2. On each node in the cluster, remove the entries in the /etc/vfstab file for the directories you are removing.

  2. From any cluster node, remove the directories by using the scnasdir command. 


    # scnasdir -r -h myfiler -d /vol/DB1 -d /vol/DB2
    -r

    Remove the directory or directories from cluster configuration.

    -h

    Is the name of the NAS device whose directories you are removing.

    -d

    Is the directory to remove. Use this option once for each directory you are removing.

    To remove all of this device's directories, specify all for the -d option: 


    # scnasdir -r -h myfiler -d all

    For more information about the scnasdir command, see the scnasdir(1M) man page.

  3. Confirm that the directories have been removed.


    # scnasdir -p
See Also

To remove the device, see How to Remove a Network Appliance NAS Device From a Cluster.