Filter
Top Products
Configuring your Environment for Software RAID
Configuring the Package Control Script and RAID Configuration File
Chapter 380
For example, let us assume that the data storage links in Figure 1-4
fail before the heartbeat links fail. In this case, after the time
specified by Link_Down_Timeout has elapsed, a package in
Datacenter1 (DC1) will continue updating the local storage, but not
the mirrored data in datacenter2 (DC2). While the communication
links must be designed to prevent this situation as far as possible,
this scenario could occur and may last for a while before one of the
sites fails.
NOTE For more information on how access to disks is disabled in certain
failure scenarios, see “Setting the Value of the Link Down Timeout
Parameter” on page 69.
Let us consider a few failure scenarios and the impact of different
RPO_TARGET values. The discussion below is based on the timeline
and events shown in Figure 3-1.
Figure 3-1 RPO Target Definitions
To ensure that no data is lost when a package fails over to DC2 and
starts with only DC2's local storage, t2 must occur between t0 and t1.