When using an Adaptec AHA-154x Cx SCSI HBA during installation of the IA release, you might see a message during the MDB device probe that says failed to initialize adapter after the probe has correctly identified the card. There are a variety of reasons for this error, but in all cases the error is because of misconfiguring the card.
To correct the problem, press Ctrl-A during boot to enter the 154x BIOS configuration utility. Choose the Configure/View Host Adapter Settings option, then press the F6 key to return the adapter to its factory default settings.
After doing this, reconfigure the adapter using the instructions contained in the IA Device Configuration Guide or Driver Update Guide, if applicable. It is especially important that the adapter be configured to use DMA 6. Note that it must be changed from the default of DMA 5.