Hitachi MK-96RD626-07 - Manual (Page 68)

3-12 Preparing for Universal Volume Manager Operations
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
When the amount of I/Os from the host to the external volume exceeds the
maximum amount of I/Os that the external storage system can accept, the
commands from the host to the local storage system may possibly be
timed out. As you configure the system using the external volumes,
consider the capability for the I/O amount of the external storage system.
• When you execute the commands of the USP V/VM program products to
the mapped external volume and thus too many I/Os are issued to be
processed by the external storage system, the commands may possibly be
timed out and an error may occur.
When the amount of I/Os from the program products to the external
volume exceeds the maximum amount of I/Os that the external storage
system can accept, the commands from the program products may
possibly be timed out and an error may occur. As you configure the system
using the external volumes, consider the capability for the I/O amount of
the external storage system.
• When you use an external volume from the host, note the Path Blockade
Watch time for the external volume. If the Path Blockade Watch time is
longer than the timeout period of the host command, the commands from
the host may possibly be timed out when the power supply is off or when
an error occurs for the external storage system. If the host I/O is a
significant concern, make sure that the Path Blockade Watch time of the
external volume is the same as or shorter than the timeout period of the
host command.
RAID Level Considerations
In the internal processing, the RAID level of the external volume is handled as
RAID-1 across the board. The bar (−) is displayed on the Storage Navigator
windows. The RAID level of external volumes is reported as RAID-1 when
information about external storage system is reported to the higher-level
device (OS).
Thunder 9500V Series Guidelines
When you use the Thunder 9500V series storage system as an external
storage system, the following versions are recommended. If you use a 9500V
storage system whose version is earlier than the following versions, the
information about the SATA drive may not be displayed correctly.
• For Thunder 9530V, Thunder 9520V, Thunder 9570V: version 0658 or
later.
• For Thunder 9580V, Thunder 9585V: version 1658 or later.