HP XP7 Storage - Manual (Page 30)

Selection of monitoring objects
Select the desired monitoring objects in the Performance Objects field.
Item on right side of Monitor
Data field Item on left side of Monitor
Data field Item on right side of Object
field Item on left side of Object
field
None Write Pending Rate (%) None Cache
Access path usage statistics
Function
The access paths are the paths through which data and commands are transferred within a storage
system. As shown in the following figure, the channel adapters (CHAs) (also called front-end
directors) in the HP XP7 Storage control the transfer of data between the hosts and the cache
memory, and the disk adapters (DKAs) (also called back-end directors) control the transfer of data
between the cache memory and the data drives, as shown below. Data transfer does not occur
between the channel adapters and disk adapters. Data is transferred via the CM package (cache
switch) to the cache memory.
When hosts issue commands, the commands are transferred via the channel adapters to the shared
memory (SM). The content of the shared memory is checked by the disk adapters.
Performance Monitor tracks and displays the usage rate for the following access paths.
•
Access paths between channel adapters and the CM package (CHA cache)
•
Access paths between disk adapters and the CM package (DKA cache)
•
Access paths between the MP blade and the CM package (MP blade cache)
•
Access paths in the CM package (cache)
Storing period
Short-Range or Long-Range can be specified.
Selection of monitoring objects
Select the desired monitoring objects in the Performance Objects field.
Item on right side of Monitor
Data field Item on left side of Monitor
Data field Item on right side of Object
field Item on left side of Object
field
None Usage Rate (%) CHA cache Access Path
None Usage Rate (%) DKA cache
None Usage Rate (%) MP blade cache
None Usage Rate (%) Cache
30 Performance Monitor data