HP XP P9500 Storage - Manual (Page 35)

Figure 18 When the external volume capacity is bigger than the basic capacity of specified
emulation type (example of the OPEN-3 emulation type)
Figure 19 When the external volume capacity is smaller than the basic capacity of specified
emulation type
Guidelines for mainframe volumes
•
If you plan to use the mapped external volume from the mainframe operating system (for
example, the volume is mapped with the setting of 3390-x mainframe emulation type), you
need to select the external volume that consists of one LDEV or you need to adjust the capacity
of the external volume to be mapped beforehand.
If multiple LDEVs exist in one external volume and if a lot of I/Os are made to these LDEVs,
the read, write commands may become timeout. When the commands become timeout, the
SIM (21D2xx) is reported.
•
When you use the mapped external volume from the mainframe operating system, set the MIH
(missing interrupt handler) timer to 45 seconds (which is the recommended value).
Volume attribute guidelines
•
The external volume attributes for all the LDEVs created in an external volume are all set the
same. The attributes are taken over, when the LDEVs are reconfigured using the Virtual
LVI/Virtual LUN function.
•
The Cache Mode becomes the same for all the LDEVs in one external volume.
•
The attributes that are set for the external volume originally on the external storage system
side (such as the port security, the LUN security, the Volume Retention attributes, and so on)
are not kept (on the local storage system side), when the external volume is mapped as an
internal virtual volume. If the original attributes are required to be set, set the attributes on the
mapped external volume from the local storage system side.
Guidelines for External Storage operations 35