Fujitsu Eternus DX80 S2 User Manual page 47

Chapter 3 Setup
3.4 Data Management
Unused areas, which may be either part or all of a RAID group, are used to create new volumes
that are then added together (concatenated) to form a single large volume.
This section describes the restrictions and notes on using LUN Concatenation.
For details on the LUN Concatenation procedure, refer to "ETERNUS Web GUI User's Guide" or
"ETERNUS CLI User's Guide".
• Volumes can be specified as a target for LUN Concatenation.
• Multiple volumes can be concatenated. Up to 16 volumes can be concatenated.
• Maximum concatenated volume capacity is 128TB.
• The minimum required capacity of each volume being concatenated is 1GB.
• Conditions for volumes to be concatenated are as follows:
-
-
• LUN Concatenation cannot be performed under the following conditions:
-
-
-
• It is possible to add extra volumes to an already concatenated volume.
• After concatenation, any number of formatting processes can be started at once.
• Because the server-side LUNs are not changed by volume concatenation, an OS reboot is
not required. However, this function only expands the volumes in the ETERNUS DX Disk
storage system. Server-side recognition and volume expansion is OS dependent.
• The logical unit number of each concatenated volume does not change and remains
accessible from the server before, during, and after the concatenation.
• If the power is turned off or an electrical power outage occurs during LUN Concatenation, the
concatenation will simply continue the next time the power is turned on.
• It is recommended that the data on the volumes that are to be concatenated be backed up
first.
• When LUN Concatenation is used to increase the volume (LUN) capacities, note that the
increased size of the expanded volumes may not always be dynamically re-recognized by the
server, depending on the server-side OS (type and version) being used. Refer to the
applicable OS and file system documentation before dynamically expanding the volume
capacity.
This is not necessary when building a new system after the volume capacity has been
expanded.
• A concatenated volume can be used as an OPC, EC, or QuickOPC copy source or copy
destination. It can also be used as a SnapOPC/SnapOPC+ copy source.
• When a volume that is using ETERNUS SF AdvancedCopy Manager to run backups is
expanded via LUN Concatenation, the volume will need to be registered with ETERNUS SF
AdvancedCopy Manager again.
ETERNUS DX80 S2/DX90 S2 Disk storage system User's Guide -Operation-
Only "Standard/Open" type volumes can be used for LUN Concatenation. SDV cannot be
concatenated. The encryption status of a concatenated volume is the same status as a
volume that is to be concatenated.
The RAID levels may be any that are supported by the ETERNUS DX Disk storage system
with no need for all to be the same or any other limitation. It is also possible to connect up
volumes with different RAID levels. Volumes in RAID groups with different types (such as
capacity or speed) of drives can be concatenated. However, RAID groups with the same
RAID level and same drive type are recommended for concatenated volumes to ensure
that performance is not affected.
When the volume to be concatenated contains an Advanced Copy session.
When the volume to be concatenated is a TPV.
When the number of volumes to be concatenated is fewer than the maximum number of
volumes that can be concatenated but the resulting capacity exceeds the maximum single
LUN capacity allowed by the ETERNUS DX Disk storage system.
Copyright 2011 FUJITSU LIMITED
47
P3AM-4842-01ENZ0