getting this error: An error was detected on device \device\Harddisk\1 during a paging operation

I would think it is time to ensure backups are up to date, and isolate the physical disk in the raid producing the error....

Whenever I see any DISK errors in the logs, it is time to get it to a new Disk. You dont wanna mess with drive failures....

Hard to say there, since there is limited information.  It is possible you have some corruption in your disk, but paging errors relating to hard disks are the result of the Windows writing to the pagefile.sys, which is defined in your System properties menu that you can find from the control panel.  Try defining a different logical drive for the placement of the page file.  Also, run a full check disk on each of the file systems.  Both operations require a reboot.

Information about Event ID 51
http://support.microsoft.com/kb/244780

If you really wanna get the details of teh error, but in my experience, a numerous amount of these errors is a good sign that the HDD is failing.....

Well, here is more info.   The error start occurring yesterday.  But this morning I had like hundreds of this error.  Sometime it was referring to  \device\Harddisk\0 and some other time to \device\Harddisk\1.  I could not also access the disk manager.  I was getting an error saying that it could not connect.  

The action I take was to reboot the server.  I then install Acronis true image for server and did a complete image, just to be on the safe side.  I daily backup on tape is also done.  After the reboot, I do not have anymore error and I can access with success the disk manager.  

Is it possible that the Raid controller was in limbo, and the reboot put it back to life?  Is there other diagnostic that can be done to really pin point the problem?  This serve as very critical information, and downtime is not an option.

Thank you,

If after the reboot, it was ok, then it could very well be the controller.....

I will try to upgrade the RAID controller driver and firmware.  I let you know how it goes.

I upgrade the Raid driver as well as the Raid firmware.  So far so good.  The error did not occur again.

Thank you,