NEC Storage M100 Series User Manual page 61

User Guide
For recovery of a pair whose status is fault, perform the following steps for replication.
a. Perform Forced Separate for the RV target.
b. Perform the steps to restore the previous status (Replicate → Separate, or Restore) again.
1.3.2.3 Auto Cache Flush Function
This is a function to automatically save user data, difference map, configuration information and the
like on caches to disk drives when host IO is not issued for five minutes.
If power off takes place without going through the ordinary procedure while data that has not been
written is left on caches, the backup function works to protect the data on caches. However, because
this backup function saves cached data in the flash memory by using batteries in the disk array
system, the data may get lost if battery power is not sufficient and saving data fails.
Auto Cache Flush Function assures data on caches to be written to disk drives and prevents data loss
even if a situation mentioned above arises.
Completion of Auto Cache Flush can be checked from high-speed flashing of POWER LED that
flashes every 0.2 seconds.
Release 6.0
Copy is started again. All the spaces of logical disks are targeted, which means full
copy is performed.
 When the replication function is used, it is strongly recommended that a user use
the storage system information saving function and create a replication reserved
volume by NEC Storage Manager. The capacity of the replication reserved
volume will be 8.0 GB.
 Powering off by performing the ordinary steps backs up storage system
information (differential map, etc.) in a replication reserved volume. If the disk
array system is powered off while no replication reserved volume has been
created, the state of the disk array system becomes backup. If no replication
reserved volume is used, it is recommended to power on the unit 24 hours.
The storage system information saving function is a function to back up the storage
system information such as differential map for business volumes (MV) and
replication volumes (RV) to disk drives.
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Chapter 1 Overview