Software User Manual
Table Of Contents
- HP StorageWorks External Storage XP user guide
- Contents
- About this guide
- 1 Overview of connecting external arrays
- 2 Preparing for External Storage XP operations
- System requirements
- External Storage XP requirements
- Installing External Storage XP
- Preparing for External Storage XP settings
- Powering arrays on or off
- Using mapped external LUs from the host connected to the local array
- Uninstalling External Storage XP
- Limitations on External Storage XP operations
- Figure 11 Example of external LU with 2 TB or less
- Figure 12 External LU capacity is larger than the specified emulation type’s basic capacity (OPEN-3 example)
- Figure 13 External LU capacity is smaller than the specified emulation type’s basic capacity
- Table 4 When external LU’s emulation type is OPEN
- Table 5 When external LU’s emulation type is for mainframes
- Combining External Storage XP with other HP StorageWorks products
- 3 Managing cache with external storage
- Guidelines for using cache with external storage
- Determining, setting, or changing the external LU cache mode
- Partitioning cache for external storage
- Determining the number and size of needed partitions
- Creating Cache partitions
- Changing storage system modes
- 4 External Storage XP panes
- 5 Configuring external LUs
- Overview of configuring external LUs
- Setting an external array’s port
- Setting a local array’s port attributes
- Mapping external LUs (Add LU)
- Setting alternate paths for external LUs
- Adding alternate paths by selecting multiple external LUs (Add Paths)
- Deleting alternate paths by selecting multiple external LUs (Delete Paths)
- Checking an external LU’s status (LDEV Information)
- Disconnecting external arrays or LUs
- Checking the connection status and resuming external LU operations (Check Paths & Restore Vol.)
- Restoring external LUs (LDEV Restore)
- Stopping the use of paths to an external LU by specifying an external array’s WWN (Disconnect Paths)
- Restoring paths to an external LU by specifying an external array’s WWN (Check Paths)
- Changing an external array’s port setting
- Stopping the use of paths to an external LU by specifying a local array’s port (Disconnect Paths)
- Restoring paths to an external LU by specifying a local array’s port (Check Paths)
- Deleting external LU mappings (Delete LU)
- 6 Troubleshooting NAS Blade systems that include external arrays
- 7 Remote command devices
- 8 Troubleshooting External Storage XP
- A Notes on connecting external arrays
- Connecting Thunder 9500V subsystems
- System parameters for connecting Thunder 9500V subsystems
- Relationship between serial numbers in the Device list on the LU Operation pane and Thunder 9500V subsystem models
- Relationship between the WWN of the port on the Thunder 9500V subsystem and the controller
- Path status and examples of recovery procedures (Thunder 9500V subsystems)
- Connecting TagmaStore AMS and TagmaStore WMS subsystems
- System parameters for connecting TagmaStore AMS and TagmaStore WMS subsystems
- Relationship between serial numbers in the Device list on the LU Operation pane and TagmaStore AMS and TagmaStore WMS subsystem models
- Relationship between the WWN of the port on the TagmaStore AMS or TagmaStore WMS subsystem and the controller
- Path status and examples of recovery procedures (TagmaStore AMS and TagmaStore WMS subsystems)
- Connecting XP12000/XP10000 Disk Arrays
- Connecting XP1024/XP128 Disk Arrays
- Connecting XP512/XP48 Disk Arrays
- Connecting HP 200 Storage Virtualization System as external storage
- Connecting EVA arrays
- Connecting Thunder 9500V subsystems
- B Required volume capacity for emulation types
- C Adjusting volume capacity for copy pair setting
- D Using an XP12000/XP10000/SVS200 with an EVA3000/5000 external storage
- E Configuring MSA1000/1500 as external arrays
- Index
22 Preparing for External Storage XP operations
restricted to the storage management logical partition (SLPR) the CLPR belongs to. For more
information about CLPRs and SLPRs, see the HP StorageWorks XP Disk/Cache Partition user guide.
Alternate paths
When mapping an external LU as an internal LDEV, paths are set from the internal LDEV to the external
LU.
If two or more paths to the external LU are equipped from different clusters, the number of paths you set
when mapping the volume are available. If one path is equipped, only that path is available.
You can set up to eight paths to each external LU, including paths automatically set. Among the paths to
the external LU, the path with the highest priority is called the primary path, and other paths are alternate
paths.
Alternate path modes include Single mode and Multi mode. The alternate path mode, Single mode or
Multi mode, depends on the connected external array. For Single mode, only the path with the highest
priority (primary path) is used to execute I/Os to the external LU. When an error occurs in the primary
path, the path with the second highest priority is used (that is, no per-LU dynamic load balancing across
paths). For Multi mode, all set paths are used at the same time. The paths are used to execute I/Os to the
external LU, distributing the work load (round-robin processing).
For example, when an external LU volume with an alternate path in Single mode is mapped to an internal
LDEV using External Storage XP, host I/O operations to the external LU via the local array are normally
enabled using the mapped path. If the mapped path is not available (for instance, during array
maintenance or following a failure in the channel processor), the path is switched automatically to the
alternate path (if available). As long as an alternate path is available, host I/O operations continue as
usual, even when an error occurs in the original path.
NOTE: When the primary path cannot be used for the length of the Path Blockade Watch timer (for
example, 180 seconds), the path is switched to an alternate path.
If you have not configured any alternate paths, host I/O operations are suspended when the primary path
becomes unavailable (such as during array maintenance operations or following a failure in the channel
processor).
HP recommends configuring alternate paths for safer operation and increased bandwidth. For
instructions, see ”Setting alternate paths for external LUs” on page 86.
You can set alternate paths when the external LUs are mapped as the internal LDEVs (see ”Mapping
external LUs (Add LU)” on page 73). You can also set alternate paths after completing the mapping
operation (see ”Setting alternate paths for external LUs” on page 86).
Example of an alternate path configuration
Figure 2 shows an example of an alternate path configuration. In Figure 2, external array ports WWN A
and WWN B are connected to CL1-A and CL2-A, respectively, which are designated as external ports in