Lun Concatenation - Fujitsu Eternus DX80 S2 User Manual

Chapter 3 Setup
3.6 Optimizing Volume Configurations
• LDE can be performed on a RAID group that contains an Advanced Copy target (copy source
or copy destination) volume.
• Capacity expansion and changing the level of a RAID group can be performed at the same
time.
• LDE cannot be performed on a RAID group that belongs to a TPP or a FTRP. To expand the
capacity of a RAID group that belongs to a TPP or a FTRP, perform RAID Migration.
• Since the data cannot be recovered after the failure of LDE, back up all the data of the
volumes in the target RAID group to another area before performing LDE. If LDE fails, recover
using this backup data.
• Volumes cannot be added to the target RAID groups while LDE is running. Volumes can be
added after LDE is complete. Volumes cannot be deleted from the target RAID groups while
LDE is running.
• If the power is turned off or an electrical power outage occurs during LDE, the process will
simply continue when the power is restored.
3.6.3

LUN Concatenation

LUN Concatenation is a function that is used to add new area to a volume and so expand the vol-
ume capacity available to the server. The ability to concatenate widely distributed free areas in
the ETERNUS DX Disk storage system allows efficient use of the drive capacity.
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:
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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.
LUN Concatenation cannot be performed when the drive type for the RAID group to which
the concatenation source volume belongs and the drive type to which the concatenation
target volume belongs do not match.
• When the concatenation source volume is configured with SAS disks or Nearline SAS
disks, volumes that are configured with SAS disks or Nearline SAS disks can be
concatenated.
• When the concatenation source volume is configured with SSDs, volumes that are
configured with SSDs can be concatenated.
Copyright 2012 FUJITSU LIMITED
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