HP StorageWorks XP24000/XP20000 for Compatible Extended Remote Copy (XRC) Software User's Guide (T5238-96001, March 2008)

This level of control is performed when the sidefile capacity is equal to or larger than the level-3
threshold.
Sidefile puncture can occur. The session for the sidefile, containing the maximum capacity in
the cache in the CLPR, is suspended.
Figure 14 Controlling the Amount of Write Data
• Do not Block (Volume Level)
Use to specify whether the storage system should control the amount of data to be written to the
specified volume:
• Enable radial button
The storage system will not control the amount of data to be written to the specified volume.
Therefore, write I/Os from hosts is not put in a wait status.
Note : Do not Block (Volume Level) is always set to Enable when Block Option is set to Volume
Level.
• Disable radial button
Depending on the sidefile capacity, the storage system will perform one of the following four
levels of control of the amount of write data (see Figure 14 on page 35).
• Level 0
This level of control is performed when the sidefile capacity is smaller than the level-1 threshold.
If Level 1 Sleep is set to Enable, write I/Os to volumes are put in a wait status according to the
threshold for the number of record sets per volume; the threshold is specified by SDM, and the
default threshold is 0x500.
If Level 1 Sleep is set to Disable, write I/Os to volumes will not be put in a wait status.
• Level 1
This level of control is performed when the sidefile capacity is equal to or larger than the level-1
threshold, and is smaller than the level-2 threshold.
Write I/Os to volumes are put in a wait status by command retry when the sleep wait threshold
(for example, level-1 threshold) is exceeded.
• Level 2
XP24000/XP20000 for Compatible Extended Remote Copy (XRC) Software User's Guide 35