HP XP P9500 Storage - Manual (Page 28)

Access paths usage statistics
Function
An access path is a path through which data and commands are transferred within a storage
system.
In a storage system, channel adapters control data transfer between hosts and the cache memory.
Disk adapters control data transfer between the cache memory and hard disk drives. Data transfer
does not occur between channel adapters and disk adapters. Data is transferred via the ESW (PCI
Express Switch adapter) to the cache memory.
When hosts issue commands, the commands are transferred via channel adapters to the shared
memory (SM) . The content of the shared memory is checked by disk adapters.
Performance Monitor tracks and displays the usage rate for the following access paths.
•
Access paths between channel adapters and the cache switch (CHA ESW)
•
Access paths between disk adapters and the cache switch (DKA ESW)
•
Access paths between the cache switch and the cache memory (Cache ESW)
•
Access paths between the MP blade and the cache switch (MP Blade ESW)
Figure 5 Access paths
Storing period
Short-Range or Long-Range can be specified.
Selecting of monitoring objects
Select monitoring objects in Performance Objects: field. The combination of items is shown as
follows.
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 ESW Access Path
None Usage Rate (%) DKA ESW
None Usage Rate (%) MP Blade ESW
None Usage Rate (%) Cache ESW
28 Working with graphs