Avago Technologies Cache Protection for RAID Controller Cards - Manual (Page 130)

Avago Technologies
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Cache Backup Products for MegaRAID SAS+SATA RAID Controllers User Guide
May 2015 Chapter 3: Monitoring and Managing Battery Backup Units and CacheVault Modules
Transferring Cached Data from a Failed Controller
3.4 Transferring Cached Data from a Failed Controller
If you are using a MegaRAID controller with an iTBBU03 unit and the RAID controller fails when there is data in the
cache that has not been written to disk, you can save the data. To do so, remove the BBU unit from the failed RAID
controller and install it on a new MegaRAID controller. For the data to be saved, the following conditions must be met:
 The new RAID controller on which you install the BBU unit must be the same model as the failed RAID controller.
 The replacement RAID controller must have a cleared configuration.
 The new RAID controller must be connected to the same disk drives as the original configuration.
Follow these steps to use the transportable BBU unit to transfer cached data from a failed controller to a new
controller:
WARNING Be sure to ground yourself before touching the RAID controller and the
transportable BBU unit.
1. Turn off the power to the computer system and disk drives.
2. Remove the failed RAID controller from the system.
3. Remove the transportable BBU unit from the failed RAID controller.
4. Install the transportable BBU unit on the replacement RAID controller.
5. Install the replacement RAID controller in the computer and connect it to the disk drives.
6. Turn on the power to the computer.
The replacement RAID controller then reads the disk configuration into NVRAM and flushes the cache data to the
virtual drives.