Write Caching

Not sure if I have my array setup correctly. Trying to setup Exchange 2003
on Windows 2003 cluster. 2 poweredge 1850 with PERC 4DC to connect to a
PowerVault 220s DAS. 3 raid arrays. 2 RAID 1 arrys and a RAID 5 array. The
PERC 4DC are in cluster mode and by default set to write through caching.
Article below indicates that write back caching on a controller is acceptable
as long as you have battery backup on the controller. Not sure of the write
back caching on the disks though.

http://support.microsoft.com/default.aspx/kb/288700

I have two questions.

1) I get the following errors sometime when I try and failover the cluster

Event Type: Warning
Event Source: Ftdisk
Event Category: Disk
Event ID: 57
Date: 5/26/2005
Time: 4:57:59 PM
User: N/A
Computer: NODE2
Description:
The system failed to flush data to the transaction log. Corruption may occur.

Event Type: Warning
Event Source: Ntfs
Event Category: None
Event ID: 50
Date: 5/26/2005
Time: 4:57:46 PM
User: N/A
Computer: NODE2
Description:
{Delayed Write Failed} Windows was unable to save all the data for the file
.. The data has been

lost. This error may be caused by a failure of your computer hardware or
network connection. Please

try to save this file elsewhere.

2) Wouldn't write back caching even with battery backup still not be a good
idea? If there is data in the write cache when a failover initiates,
wouldn't there be a possiblity of data lose since the controller on the other
node will not have the same data in its controller cache?
.

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