Questions/confusions on enabling write cache

Legacy777,

 

First, on the error "The driver detected that the device \Device\Harddisk0\DR0 has its write cache enabled. Data corruption may occur."

 

This could happen if a computer or power failure occurs that would prevent your computer from shutting down properly. This is because until the cached data is written to disk, the last few write operations were reported to the operating system as being complete by the hardware, but the hardware still contains the data in its physical memory. Should a power loss occur, those last few write operations may not take place, possibly leading to data loss or file system damage. However, the perc has a battery backup so the cache can be written to the disks if a power outage does occur.

 

As for the settings on the Virtual Disk, I would leave them unless you are seeing performance issues then you could change the Write policy to see if increases any.

Dennis,

Thanks for the comments.  What about if the system get's powered down incorrectly, ie hit the power button or reset button while still connected to power?  Would that present a problem with the cache?

 

Also, quick question about these settings in the SAS Raid Storage Manager

 

Yeah I agree I wouldn't want to "hard" reboot/shutdown the server frequently, but it can happen once in a while.

 

I do not have frequent power outages, and do have a good UPS on the server, so I'll probably just leave those settings alone.

 

Again, thanks for the comments Dennis.

Josh

If it is being powered down incorrectly the battery should provide enough time to write the data to disk.  Obviously, I don't recommend doing this on a regular basis though.

 

Disk Cache Policy, i would leave alone.  As for the Write through for failed/missing battery, You could change this if you do have frequent power outages, incorrect shutdowns.  This way it does not use cache when there is not a battery backup.