HP StorageWorks XP Remote Web Console Software User Manual
Page 43
If a LUSE volume consists of multiple external volumes and one external volume has lower
performance than the other volumes, the lower performance of the volume affects the perform-
ance of the LUSE volume.
•
• When an external volume which is a component of a LUSE volume is blocked, data reliability
of the LUSE volume will deteriorate because the LUSE volume has both accessible area and
inaccessible area from a host.
• When you disconnect an external volume or resume the use of an external volume, you need
to perform the operation at the same time on all the external volumes which are components
of the LUSE volume.
•
Do not update a volume being used or operated by XP Flex Copy. Also do not update the external
LU on the external array side.
•
You can delete up to 256 mappings for external LUs at one time.
•
Operations cannot be performed if some parts of the local array are blocked. In this case, restore
blocked parts of the local array, and retry the operation.
•
When using the Thunder 9500V series subsystem as an external array, the following versions are
recommended. If you use a 9500V array with a version that is earlier than the following versions,
the SATA drive information might not display correctly.
• For Thunder 9530V, Thunder 9520V, Thunder 9570V: version 0658 or later
• For Thunder 9580V, Thunder 9585V: version 1658 or later
•
When you use TagmaStore AMS 2000 series (AMS2100/2300/2500) subsystem as an external
disk array, unnecessary load to the external disk array should be avoided. When the TagmaStore
AMS 2000 series subsystem is used as an external disk array, the path mode between disk array
is Multi mode. Therefore, when there are a lot of external paths and mapping volumes, the load
to the external subsystem becomes high and some commands from host to XP24000 or some
commands from XP24000 to the external disk array may time out.
To keep the load proper, the following is recommended.
• Define volumes of each TagmaStore AMS2000 series disk array to set external path number
to two. In that case, set the paths to the ports of each controller of TagmaStore AMS2000
series subsystem.
• Set the queue of commands which are issued at the same time from one AMS2000 series disk
array to 500 or less. The calculation formula to derive the number of the queue commands
per AMS2000 series disk array is shown as follows. (number of queues) x (number of paths
of external volumes) x (number of external volumes which issue commands at the same time)
< 500 For more information about setting the queue of commands (see “
•
When you use external volumes of TagmaStore AMS2000 series disk array with copy software,
the copy operation needs to be distributed to two or more RAID groups. There is an upper bound
to the number of pairs, which can be used for initial copy or resynchronization. Therefore, the
copy operation may focus on a specific RAID group according to the order of the copy operation
when the copy operation is performed to two or more external volumes. The drive of the TagmaStore
AMS2000 series disk array may become a bottleneck, which causes insufficient performance,
when the copy operation focuses on a specific RAID group.
•
Do not map multiplatform volumes of external arrays as internal LDEVs.
•
After executing the Check Paths & Restore Vol., Disconnect Subsystem, or Disconnect Volume
command, click the Refresh button (
) on the XP Command View Advanced Edition Software or
Remote Web Console main pane to update the information, and check the current status.
•
When the external LU's status is Blockade, execute the Check Paths & Restore Vol. command.
XP External Storage Software User Guide
43