Maintenance windows that require change control board approval for Windows Server HCI updates must consider the total attended and unattended time. Typically, organizations require maintenance windows during LCM operations because update failures have the potential to affect the normal response times that end users experience. On the four-node cluster in the lab, the benefit of the automated approach meant a 40 percent shorter maintenance window as compared with the manual approach.
Note: Maintenance windows are not the same as scheduling downtime. Dell EMC OpenManage Integration places target nodes into maintenance mode, which migrates running VMs to other online hosts. This process ensures that there is no application downtime. However, most organizations still prefer to schedule maintenance windows when production systems are being updated.
In our lab testing of the automated process, each node beyond the first node took 45 minutes in total—including both unattended and attended time—to complete the update. (The first node took a little longer due to preparation tasks.) Using the manual process, each node beyond the first node took about 71 minutes total time to complete.
The following figure compares the total maintenance windows for automated and manual updates:
To put this time savings into perspective, consider the time consumed by LCM tasks within large enterprise IT organizations. Some enterprises use Windows Server HCI to solve their business challenges in globally distributed remote branch offices and regional data centers. The challenges presented by LCM activities increase exponentially with multiple clusters. Dell Technologies releases quarterly updates for Dell EMC HCI Solutions for Microsoft Windows Server and recommends applying the updates as soon as possible. Based on the lab testing, an IT organization that must update 20 four-node clusters each quarter could expect to save almost an entire week of time per year by following the automated approach instead of the manual approach.