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Storage Maintenance Window

Storage Maintenance Window (Erl, Naserpour)

How can access to data in a cloud storage device be preserved during a maintenance outage?

Problem

Hardware maintenance on cloud storage devices can require shutting down the device, resulting in loss of data access and disruption of service.

Solution

An outage prevention system is created to temporarily move the data without interruption during maintenance and other types of outages.

Application

LUN migration is applied to temporarily transfer data to a separate cloud storage device during the maintenance window.

Problem

Cloud storage devices subject to maintenance and administrative tasks may need to be temporarily shut down, thereby causing an outage to cloud service consumers and IT resources that require access to the devices and the data they host.

Storage Maintenance Window: The maintenance task carried out by a cloud resource administrator causes an outage for the cloud storage device. Resultantly, the cloud storage device becomes unavailable to cloud service consumers.

Figure 1 - The maintenance task carried out by a cloud resource administrator causes an outage for the cloud storage device. Resultantly, the cloud storage device becomes unavailable to cloud service consumers.

Solution

Prior to a cloud storage device undergoing a maintenance outage, its data can be temporarily moved to a duplicate, secondary cloud storage device. Cloud service consumers are automatically and transparently redirected to the secondary cloud storage device and are unaware that the primary cloud storage device has been taken off-line.

Application

Live storage migration is used to convert the data as a whole into an isolated mode and move it to the secondary cloud storage device, as follows:

  1. The target secondary cloud storage device is identified.
  2. The data replication process is configured.
  3. LUNs that require replication are selected.
  4. The service broker is configured to redirect the cloud consumers’ requests to the secondary storage, should the primary one fail.
Storage Maintenance Window: The steps carried during to provide constant data access during a maintenance outage window.

Figure 2 - The steps carried during to provide constant data access during a maintenance outage window.

  1. The cloud storage device is scheduled to undergo a maintenance outage.
  2. Live storage migration moves the LUNs from the primary storage device to a secondary storage device.
  3. When the LUN’s data has been migrated, requests for the data are forwarded to the duplicate LUNs on the secondary storage device.
  4. The primary storage is powered off for maintenance.
  5. When it is confirmed that the maintenance task on the primary storage device has been completed, the primary storage is brought back online. Live storage migration subsequently restores the LUN data from the secondary storage device to the primary storage device.
  6. When the LUN migration is completed, all data access requests are forwarded back to the primary storage device.

NIST Reference Architecture Mapping

This pattern relates to the highlighted parts of the NIST reference architecture, as follows:

Storage Maintenance Window: NIST Reference Architecture Mapping
Storage Maintenance Window: NIST Reference Architecture Mapping
CloudSchool.com Cloud Certified Professional (CCP) Module 5: Advanced Cloud Architecture.

This pattern is covered in CCP Module 5: Advanced Cloud Architecture..

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