Changing the Failover Alert Delay

Use Failover Alert Delay to change the failover alert delay for a .

The failover alert delay lets you delay the logging of a critical event if the multipath driver transfers  to the non-preferred . If the multipath driver transfers the virtual disks back to the preferred RAID controller module within the specified delay period, no critical event is logged. If the transfer exceeds this delay period, then a virtual disk-not-on-preferred-path alert is issued as a critical event. This option also can be used to minimize multiple alerts when many virtual disks fail over because of a system error, such as a failed .

The virtual disk-not-on-preferred-path alert is issued for any instance of a virtual disk owned by a non-preferred RAID controller module and is in addition to any other informational or critical failover events. Whenever a virtual disk-not-on-preferred-path condition occurs, only the alert notification is delayed; a needs attention condition is raised immediately.

To make the best use of this feature, set the failover alert delay period such that the host driver failback monitor runs at least once during the alert delay period. Note that a virtual disk ownership change might persist through the alert delay period, but correct itself before you can inspect the situation. In such a case, a virtual disk-not-on-preferred-path alert is issued as a critical event, but the array will no longer be in a needs-attention state. If a virtual disk ownership change persists through the failover alert delay period, refer to the Recovery Guru for recovery procedures.

Firmware Downloads

• Virtual Disk path changes that occur as a normal part of a RAID controller module  download typically do not result in a virtual disk-not-on-preferred-path alert notification. After the download has completed, the delayed virtual disk distribution process is activated to determine whether all virtual disks were restored to the preferred path during the download. If any virtual disks are not on the preferred path, a critical event is logged and an alert notification is issued.
• Under  a virtual disk-not-on-preferred-path alert might occur after a firmware download has completed if the failover driver is using the non-preferred path because of virtual disk ownership changes during the firmware download. The AVT failover driver continues to use the non-preferred path for some period of time, even though the virtual disks have been restored to their preferred owner. If the driver does not correct itself before the alert delay period expires, a critical event is logged. To prevent such unexpected alert notifications, ensure the alert delay period and the multipath driver failback probe interval are configured such that the probe runs at least once during the delay period.
• Under , such alerts do not occur after firmware downloads because the RDAC failover driver detects virtual disk ownership changes and directs I/O down the preferred paths.

Important:

• The Failover Alert Delay option operates at the storage array level, so one setting applies to all virtual disks.
• The Failover Alert Delay option is reported in minutes in the  as a storage array property.
• The default failover alert delay interval is five minutes. The delay period can be set within a range of zero to 60 minutes. Setting the alert delay to a value of zero results in instant notification of a virtual disk not on the preferred path. A value of zero does not mean alert notification is disabled.
• The failover alert delay is activated after RAID controller module start-of-day completes to determine if all virtual disks were restored during the start-of-day operation. Thus, the earliest that the not-on-preferred path alert will be generated is after boot up and the configured failover alert delay.

Related Topics

Learn About the Failover Alert Delay

Viewing a Storage Array Profile