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Draft Document for Review January 23, 2011 12:42 pm
7759ch_Mirror.fm
3.2.3 Mirroring status
The status of a mirror is affected by a number of factors such as the links between the XIVs or
the initialization state.
Link status
The link status reflects the connection from the master to the slave volume or CG. A link has
a direction (from local site to remote or vice versa). A failed link or a failed secondary system
both result in a link error status. The link state is one of the factors determining the mirror
operational status. Link states are as follows:
򐂰 OK: link is up and functioning
򐂰 Error: link is down
Figure 3-5 and Figure 3-6 depict how the link status is reflected in the XIV GUI, respectively.
Figure 3-5 Link up
Figure 3-6 Link down
If there are several links (at least two) in one direction and one link fails, this usually does not
affect mirroring as long as the bandwidth of the remaining link is high enough to keep up with
the data traffic.
Monitoring the link utilization
The mirroring bandwidth of the links must be high enough to cope with the data traffic caused
by the changes on the master volumes. During the planning phase, before setting up
mirroring, monitor the write activity to the local volumes. The bandwidth of the links for
mirroring must be as large as the peak write workload.
Chapter 3. Remote Mirroring
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