Before upgrading your clustered storage systems, verify that the cluster is properly configured by using the Cluster Configuration Checker. Identify and resolve any cluster configuration issues before continuing with the upgrade.
The Cluster Configuration Checker is a Perl script that detects errors in the configuration of a pair of clustered NetApp storage systems. The script is available on the NetApp on the WebTM (NOW) site at http://now.netapp.com/NOW/download/tools/cf_config_check/.
See also the chapter on cluster management in the Cluster Installation and Administration Guide.
The following methods are available for upgrading cluster partners:
Depending on the nature of the upgrade, nondisruptive cluster upgrades ensure better storage system availability than single system or standard cluster upgrades.
When planning for your upgrade, evaluate the advantages and disadvantages of each method. Each method is described in this section.
Note
You cannot use the nondisruptive method to upgrade clusters to Data ONTAP 7.1 or later from a Data ONTAP release earlier than 6.5.3. To do this upgrade for releases earlier than 6.5.3, you must use the standard method of upgrading.
In a nondisruptive upgrade (also called a rolling upgrade), clustering technology is used to enable a takeover storage system to assume the functions of the "failed" partner while it is being upgraded. There is a takeover and giveback operation for each cluster node. Because the cluster partner node fulfills service requests during the "failed" storage system's upgrade, no disruption in service is experienced by the clients.
In addition, because the takeover storage system assures continuous availability of the "failed" system's disks, more extensive upgrades requiring a system halt--such as system firmware upgrades and hardware adapter replacements--can be performed without disrupting services based on stateless protocols.
Note
For storage systems with FCP or iSCSI hosts, nondisruptive upgrades within Data ONTAP release families (for example, from Data ONTAP 7.1 to Data ONTAP 7.1.1) are currently supported and can be performed as documented in this guide. Nondisruptive upgrades between Data ONTAP release families (for example, from Data ONTAP 7.0 to Data ONTAP 7.1) will be supported in the future through NetApp Professional Services to ensure that the upgrade is completed seamlessly for the FCP or iSCSI hosts.
Nondisruptive clustered upgrades are recommended to minimize service disruption when one or more of the following is being performed:
Note
See the Cluster Installation and Administration Guide for more information about changing system hardware nondisruptively.
Before undertaking a nondisruptive upgrade procedure, make sure that you do the following:
Nondisruptive upgrades require more planning and procedural steps than standard upgrades. Make sure to thoroughly review this document before starting a nondisruptive upgrade. See especially Appendix D, Optimizing Service Availability During Upgrades.
You can verify that your clustered storage systems are properly configured by running the Cluster Configuration Checker as described in Before upgrading clustered storage systems.
Configure client timeout settings to optimize availability as described in Service and protocol considerations.
If you have enabled automatic giveback by setting the cf.giveback.auto.enable option to On, you must set this option to Off before upgrading your cluster using the nondisruptive method. After the upgrade procedure, reset this option to On (if desired).
Disk firmware upgrades take place automatically in the background when RAID-DP protection is configured. Services and data continue to be available during the disk firmware upgrade. For more information, see Service availability during disk firmware upgrades.
You should not use nondisruptive upgrades in the following circumstances:
Because CIFS is session-oriented, sessions must be terminated before upgrade procedures to prevent data loss.
Because these protocols are session-oriented, outstanding sessions must complete, and these services must be disabled in order to use nondisruptive upgrades.
Standard disk firmware upgrades automatically take disks in RAID4 aggregates offline until the upgrade is complete. Services and data are unavailable until they are back online. For more information, see Service availability during disk firmware upgrades.
Note
If you upgrade RAID protection to RAID-DP, disk firmware upgrades take place in the background and are non-disruptive.
On diskette-based clustered storage systems, the takeover and giveback operations are much slower than on CompactFlash-based systems and possibly slower than rebooting.
For these conditions, standard upgrades are recommended.
In a standard upgrade, the cluster is disabled and each node is updated. When the cluster is disabled, each node behaves as a single-node (non-clustered) storage system; in other words, system services associated with that node are interrupted for as long as it takes the system to reboot.
In general, standard cluster upgrades are most appropriate if you schedule regular downtime for your storage systems. Other maintenance upgrades, such as system firmware and hardware, can also take place when the cluster is disabled.
Standard cluster upgrades must be used for upgrades to Data ONTAP 7.1 or later from releases earlier than Data ONTAP 6.5.3.
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File: 2upgrad4.htm
Last updated: 16-Dec-2005 18:19:09