System hangs during READ / WRITE operations immediately after upgrade to InveStore v4 or greater


In InveStore v4 or greater, Pegasus has made a change in the Maximum Scatter/Gather list in the Windows registry to improve storage performance. If during the installation process the wrong SCSI Driver Name is identified, the value may not have been correctly entered in the Windows registry.


To correct this, open Windows RegEdit and go to the following key:




Where the DriverName is the name of the host adapter card driver you are using to control the storage library (E.g. AIC78XX). Modify the key MaximumSGList and add the value "ff". Restart the server.


This may also occur if you should change the SCSI card in your server after installing InveStore v4 or greater.