Logical Device Expansion (Lde); Lun Concatenation - Fujitsu Eternus DX80 S2 User Manual

Chapter 3 Setup
3.4 Data Management
• When expanding the capacity of TPVs, use the Thin Provisioning Volume expansion function
before RAID Migration starts or after RAID Migration is complete.
• When RAID Migration 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.
3.4.2

Logical Device Expansion (LDE)

Logical Device Expansion (LDE) allows the capacity of an existing RAID group to be dynamically
expanded by the addition of extra drives. By expanding the capacity of existing RAID group, a
new volume can be added without having to add new RAID groups.
This section describes the restrictions and notes on using LDE.
For details on the LDE procedure, refer to "ETERNUS Web GUI User's Guide" or "ETERNUS
CLI User's Guide".
• A RAID group can be specified as a target for LDE.
• Multiple LDEs cannot be performed simultaneously.
• LDE can be performed if the new RAID group capacity is the same or larger than the old
capacity.
• When adding drives, use a drive with a capacity that is the same or with a larger capacity than
the drives in the RAID groups that are targets for LDE. After LDE completes, all the drives in
the target RAID groups are recognized as having the same capacity as the drive with the
smallest capacity in the RAID group. The rest of the capacity in the drives that have a larger
capacity cannot be used.
• 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 TPV. To expand the capacity of
a RAID group that belongs to a TPV, 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.
3.4.3

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.
ETERNUS DX80 S2/DX90 S2 Disk storage system User's Guide -Operation-
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