I replaced the RAID card in cdsfs1 with a new one. While I had the chassis open, I took the opportunity to vacuum out all the bugs and check the interior cable connections. Even so, upon booting with the new card installed, was greeted by an I2c bus error from the RAID controller. So powered off the server and found a loose connection to the disk backplane, which I either missed earlier or knocked loose when addressing another loose cable earlier (it may also never have been connected properly, once reconnected the RAID controller showed temperature sensors previously not shown on the old controller). On reboot the RAID controller was now happy. But once the server booted the root drive mounted read only due to EXT4 filesystem journal errors. So rebooted once again, which forced a full fsck after which the root filesystem was happy. The RAID controller is now in the process of verifying the RAID; this is a slow process that will take at least a day. So far the system looks healthier, but the RAID verification process should provide a good burn in period.