Nexenta: Convert syspool to AHCI drivers

When using Nexenta it is highly recommended to attach the syspool disks via AHCI instead of SATA. Attaching them via SATA might cause I/O errors leading to complete outages. The only way to solve this is to replace the driver with AHCI.

Normally changing the driver for the syspool requires a complete reinstallation. However if you want to avoid this simple follow this guide:

1. Boot with Nexenta Setup CD; Choose “Rescue System”
2. when booted import the syspool with:

   zpool import -f syspool

3. Install boot loader on ALL disks belonging to the syspool, e.g. for the first disk:

   grub-install /dev/rdsk/c0t0d0s0

4. Export the syspool:

   zpool export syspool

5. Reboot

Done. The system now uses AHCI drivers.