I have a Lenovo laptop where I recently replaced the harddisk with a Intel 530 240 Gb SSD (SATA III) on which I then installed Centos 6.5 which runs just fine albeit at SATA II speed. I then replaced the DVD-drive in the Ultrabay with an identical Intel SSD, the Ultrabay-adapter apparently uses a PATA-SATA bridge so this drive would only run at PATA speed. Being a Centos newbie, I am not sure why Centos calls the first SSD sdb and the second one in the Ultrabay sda? It would seem to me that the first one, the one replacing the original harddisk, should be the main one and be called sda but clearly there is something I don't understand. In the BIOS the SSD replacing the harddisk has a higher boot order priority then the SSD replacing the DVD-drive. Suggestions? Thanks.