Fujitsu ETERNUS DX80 S2 User Manual page 46

Chapter 3 Setup
3.2 Flexible Tier (Auto Storage Layering) Setup
■ When using the FTRP balancing
The restrictions and points to note when using the FTRP balancing function are as follows:
• Balancing FTRP can be performed for FTSPs in the same TPP.
• The total number of TPV balancing, FTRP balancing, RAID Migration, and Flexible Tier Migration processes
that can be performed at the same time is 32.
• The FTRP balancing function equalizes unevenly allocated physical area in the RAID groups that configure
an FTSP. Note that migrating a physical area to a different FTSP is not available.
• If the free capacity in the FTSP becomes insufficient while FTRP balancing is being performed, an error
occurs and the balancing session ends abnormally. Note that insufficient physical capacity cannot be
replaced by other FTSPs.
• When FTRP balancing is performed, an area for the work volume (the destination FTV which has the same
capacity as the source FTV) is secured in the FTRP to which the FTV belongs. As a result, the status of the
FTRP may temporarily become alarm status (the FTRP usage exceeds the "Caution" or "Warning" threshold).
The alarm status is released when balancing is completed successfully.
• If the capacity of the FTRP is expanded during an FTRP balancing process, the balancing level might be less
than before.
• FTRP balancing cannot be performed for volumes that are undergoing Zero Reclamation.
• FTRP balancing may not be performed regardless of what FTRP balancing level is used. FTRP balancing
availability depends on the physical allocation status of FTVs.
ETERNUS DX80 S2/DX90 S2 Disk storage system User's Guide -Operation-
46
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