Additional information on pair status
You should know what happens when you split or suspend a pair.
- When a pair is split by the user or suspended by the system, the primary storage system notifies the hosts by issuing a service information message (SIM). If SNMP is installed and operational, this SIM results in an SNMP trap indicating the reason for suspension.
- When you suspend a pair, the status changes to Suspending first, and then to PSUS. When you delete a pair, the status changes to Deleting first, and then to SMPL. However, Suspending and Deleting are not displayed as the pair status in RAID Manager.
- If you split a pair in Flush mode, it takes some time for the pair status to change to
PSUS. To shorten the time, select
Purge for
Split Mode in
HDvM - SN, or execute the
pairsplit -P command in
RAID Manager before splitting a pair. If a pair is split in Flush mode, the status changes to Suspending first, and then it changes to
PSUS when all journals in the master journal are restored to the restore journal. The time for a pair to change to
PSUS can be calculated as follows (the actual time might vary depending on the internal processing status of storage systems):
time-for-Suspending (sec.) = C x U / V
where:
- C is the total capacity (GB) of the master journal volume.
- U is the usage rate of data (%) in the master journal volume.
- V is the line speed (GB/sec) between the primary and the secondary storage systems.
The total capacity (GB) can be checked in the Journals tab of the Journals window or using the raidcom get ldev command.
The data usage rate can be checked in the Performance Monitor window in Performance Monitor or using the raidcom get journal command. For details about Performance Monitor, see the Performance Manager Guide.
When using RAID Manager to monitor the time until the status changes to PSUS in Flush mode, specify a value equal to or greater than the calculated time (in seconds) for the -t option of the pairsplit command.