When External Lu's Emulation Type Is Open; When External Lu's Emulation Type Is For Mainframes - HP StorageWorks User Manual

• Table 5 and
the external LU's HDD type.
Table 5

When external LU's emulation type is OPEN

Application
Database
Online Transaction Processing (OLTP)
File operation from host
(both Read and Write)
File operation from host
(mainly Read)
Backup
Archive
Table 6

When external LU's emulation type is for mainframes

Application
Database
Online Transaction Processing (OLTP)
System volumes
(Journal, Check points)
Operation from TPF
File operation from host
(both Read and Write)
File operation from host
(mainly Read)
Backup
Archive
• The external disk array's performance and status affect the mapped external LU's Read and Write
performance. If there is a heavy load on the external disk array, the Read and Write operation's
processing speed slows. In this case, I/Os from the mainframe host might have an MIH error.
• If the host connected to the local disk array issues too many I/Os for the external disk array to process,
commands from the host might time out.
When the amount of I/Os from the host to the external LU exceeds the maximum amount of I/Os the
external disk array can accept, commands from the host to the local disk array might time out. As you
configure the system using external LUs, consider the external disk array's I/O capacity.
• When executing commands in Command View XP or XP Remote Web Console software products to the
mapped external LU and, therefore, too many I/Os are issued for the external disk array to process,
commands might time out and errors might occur.
When the amount of I/Os from the software products to the external LU exceeds the maximum amount
of I/Os the external disk array can accept, commands might time out and errors might occur. As you
configure the system using external LUs, consider the external disk array's I/O capacity.
• When using an external LU from the host, note the external LU's Path Blockade Watch time. If the Path
Blockade Watch time is longer than the host command's timeout period, commands from the host might
time out when the power supply is off or errors occur for the external disk array. If host I/O is a
36 External Storage XP for the XP12000/XP10000
Table 6 show the recommended application level for the mapped external LU according to
HDD type
FC S-ATA
Not Recommended Not Recommended
OK Not Recommended
OK OK
OK Recommended
OK Recommended
HDD type
FC S-ATA
Not Recommended Not Recommended
Not Recommended Not Recommended
Not Supported Not Supported
OK Not Recommended
OK OK
OK Recommended
OK Recommended