HP MPX200 Multifunction Router - Manual (Page 29)

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A single Global Presented Target WWPN may now present LUNs from any VPG using the
lunremap
command.
Migration to a thin-provisioned LUN
The MPX200 provides the option to create a data migration job to a thin-provisioned destination
LUN.
The MPX200 detects thin-provisioned storage based on SCSI Read capacity commands. Some
storage arrays, even though they support thin provisioning, may not indicate the support for
thin-provisioned storage in the SCSI Read Capacity response.
For migration from regular, thick-provisioned LUN, to thin-provisioned storage, HP recommends
using a space-reclamation tool on the source LUN. Space-reclamation utilities help maximize the
capacity savings on the new, thin-provisioned storage.
Recommended steps
HP recommends that you run the SRU on a file system volume prior to configuring a migration job
for a thin-provisioned destination LUN. Follow these steps to migrate to a thin-provisioned storage:
1.
Run the SRU on the file system volumes that are to be migrated using the MPX200.
2. Follow either the online or offline data migration procedure.
The migration to thin-provisioned storage option (TP settings in HP mpx Manager) has three values:
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No TP: The destination LUN is not thin-provisioned; this is the default value.
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Yes, and No Validation: Select this option when the destination LUN is known to be a
thin-provisioned storage and is known to contain all zeroes or is newly created.
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Yes and TP Validation: Select this option if you are uncertain about the data on the destination
LUN, or if the destination LUN was used earlier for storing any other data. Enabling validation
ensures that no corruptions exist because of stale data on the destination LUN. Enabling
validation creates additional processing overhead. Typically, validation is not required for a
newly created destination LUN for data migration. For remote online and offline data migration,
HP does not recommend thin-provisioning and validation.
DML
The MPX200 uses a DML to support remote migration (asynchronous replication). The DML:
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Is a critical component to support remote migration.
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Must be allocated from a highly available storage array on a local SAN.
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Must be accessible from both MPX200 blades.
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Must be accessible through multiple paths to each blade.
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Requires a minimum user capacity of 100GB (recommended), which supports up to 64 remote
migration jobs (active, scheduled, or configured) on a single MPX200 across both blades.
DML size, see Table 5 (page 30) , depends on the data change rate and how many concurrent
migration jobs are active. More than 64 remote migration jobs require a minimum of 1GB additional
user capacity for each additional job. Typically, a 164 GB DML can hold 128 DRLs. You can
dynamically add up to eight LUNs in the DML pool. To remove the DML from the pool, ensure that
all remote migration jobs are completed or removed. Each LUN in a DML pool must be smaller
than 2TB.
Migration to a thin-provisioned LUN 29