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REPLACING A BATTERY BACKUP UNIT ON A FC60

Dani Choufani
Valued Contributor

REPLACING A BATTERY BACKUP UNIT ON A FC60

Hi ,
I have to replace the BBU on a FC60 DISK ARRAY ,
WHAT IS THE PROCEDURE TO DO THAT WITHOUT LOOSING HE CONFGURATION ON THE CACHE ..

THANK'S
1 REPLY
Dani Choufani
Valued Contributor

Re: REPLACING A BATTERY BACKUP UNIT ON A FC60

this is the procedure :



1- Listing Disk Array IDs


amdsp -i



2- Resetting Battery Age
The battery age should be reset to zero when the battery is replaced. This ensures an
accurate indication of the age of the battery
To reset the battery age to zero, type:

ammgr -b


3- Disabling Disk Module Write Cache Enable (WCE)

To ensure optimum protection against data loss, it is recommended that Write
Cache Enable be disabled on all disks in the array. Disabling disk WCE will
impact disk array performance. However, it reduces the potential for data loss
during a power loss.
To ensure optimum data integrity, it is recommended that the Write Cache Enable (WCE)
feature be disabled on all disk modules in the array. Each disk has internal write cache
memory which is used to store data until it is written to the disk media. (This should not be confused with the array controller write cache, which is protected by the BBU.) If power to a disk is interrupted before data in write cache has been copied to the disk media, the data will be lost. To avoid this situation, the WCE feature should be disabled on all disks in the array. This ensures that data is written directly to the disk media and not stored in disk cache.
This procedure for disabling disk WCE should be executed any time a disk module is
replaced or a new disk module is added to the array. This will ensure that WCE is disabled on all disks in the array.

To disable WCE on all disks, type:
amutil -w

WCE will be disabled on all disks visible to the array controllers. Depending on the number
of disk modules in the array, this command can take up to 60 seconds to complete.

Command Example
The following example disables WCE on all disks in disk array 0000005EBD20:
amutil -w 0000005EBD20



4- Resetting Battery Age
The battery age should be reset to zero when the battery is replaced. This ensures an
accurate indication of the age of the battery
To reset the battery age to zero, type:

ammgr -b

5- Enabling Disk Write Cache Enable (WCE)

CAUTION WCE should only be enabled in environments that provide uninterruptible
power to the disk array. A loss of power to the disk array may result in data
loss with WCE enabled.
If maximum I/O performance is critical, disk WCE can be enabled on all the disks in the
array. Disk WCE enhances disk array I/O performance, but increases the possibility of data
loss during a power loss.
If WCE is enabled, this procedure for enabling disk WCE should be executed any time a
disk module is replaced or a new disk module is added to the array. This will ensure that
WCE is enabled on all disks in the array.
To enable WCE on all disks, type:

amutil -w on

WCE will be enabled on all disks visible to the array controllers. Depending on the number
of disk modules in the array, this command can take up to 60 seconds to complete.