HP StorageWorks Storage Mirroring user's guide (T2558-96073, February 2008)

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At the top of the Transmit tab dialog box, the Enable Transmission Limiting check box allows you to turn the
transmission options on or off. You can enable the transmission options by marking the
Enable Transmission Limiting
check box when you want the options to be applied, but you can disable the transmission options, without losing the
settings, by clearing that check box.
Also at the top of the
Transmit tab dialog box, the Clear All button, when selected, will remove all transmission
limitations that have been set under any of the limit types. The
Clear button will clear the settings only for the Limit
Type
selected.
3. When you schedule transmission start criteria, transmission will start when the criteria is met and will continue until the
queue is empty or a transmission stop criteria is met. Select the
Start option in the Limit Type box.
Define the start options for Storage Mirroring transmission by using any combination of the following options.
 Transmission session start—This option establishes a date and time of the day to begin transmitting data. For
example, you may want to specify a transmission time that corresponds to a low bandwidth usage time. Once started,
Storage Mirroring will continue to transmit data until the queue is empty or until another limitation stops the
transmission. Specify a
Date and Time to start transmitting data. The down arrow next to the date field displays a
calendar allowing easy selection of any date. The time field is formatted for any AM or PM time.
 Session Interval—This option begins transmitting Storage Mirroring data at specified intervals of time. This option
is used in conjunction with
Transmission session start. For example, if the Session Interval is set to repeat
transmission every 30 minutes and the
Transmission session start is set to begin transmitting at 10 p.m., if the queue
is emptied at 10:20 the transmission will stop. The start criteria is again met at 10:30 and Storage Mirroring will begin
transmitting any new data in the queue. Specify an interval for additional transmissions by indicating a length of time
and choosing minutes, hours, or days.
 Queue Threshold (percentage) and Queue threshold (bytes)—If the allocated amount of queue disk space is in use,
Storage Mirroring cannot continue to queue data causing an auto-disconnect and the potential for loss of data. To
avoid using the entire queue, you can configure Storage Mirroring to begin transmitting data to the target when the
queue reaches a certain point. This point can be defined as a percentage of the disk queue that must be in use or the
number of bytes in the disk queue. For example, if you specify 40%, when 40% of the queue is in use, Storage
Mirroring initiates the transmission process and sends the data in the queue to the target machine. The transmission
stops when the queue is empty or a Storage Mirroring stop transmission criteria is met. Or you might set a queue
threshold of 500 MB. Storage Mirroring will wait until there is 500 MB of data in the queue and then begin transmitting
the data. Like other start criteria, Storage Mirroring continues transmitting until the queue is empty or a Storage
Mirroring stop criteria is met. Specify a percentage of the disk queue and system memory that must be in use to
initiate the transmission process, and/or specify the number of bytes that must be in the source queue and system
memory to initiate the transmission process.
NOTE: A Transmission Session Start setting will override any other start criteria. For example, if you set the
Transmission Session Start and the Queue Threshold, transmission will not start until you reach the
indicated start time.