Replacing the root hard disk

You may need to replace the root hard disk if an existing disk is no longer large enough for your needs, or if it suffers a head crash or some other irreparable failure.

1. Install the new disk. If the drive is not a SCSI drive and is not identical to the original, be sure you change the BIOS settings with the setup program provided with your computer hardware to record the new disk parameters. See the documentation provided with your system hardware.

2. Start a fresh installation. From the Preparing your disk and choosing software screen, select Hard Disk Setup. From the Disk 0 Partitions and filesystems screen, select Customize. Recreate each of your old filesystems. Make the sizes of your filesystems at least as large as the originals, otherwise your backups will not fit when you restore them.

3. When you are returned to the Preparing ... screen, select Optional software. You can omit installation of all optional software by typing n for Operating system services, Graphical environment, and so on.

4. When installation is complete, put the system into single-user mode and restore your root filesystem backup. For example, to restore a cpio(C) backup, enter:
   
   cpio -imucvdB -I/dev/rct0

   If your tape drive is not yet configured, run mkdev tape to reconfigure your tape drive so that you can restore your backups. As an alternative, you can reboot and specify the appropriate bootstring for the tape device. For example, to configure a Wangtek drive:

      Boot
      : hd(40)unix ct=wangtek(0x338,5,1)
   

5. If you have a SCSI system and you changed the host adapter in addition to changing the root disk, follow these additional steps:

   
   a.

   Remove your old host adapter driver from your kernel configuration by editing the file:
   
   /etc/conf/sdevice.d/adapter

   where adapter is the name of the SCSI driver for your old host adapter (see /etc/default/scsihas for a list of host adapter drivers).

   
   b.

   Change the Y to N in the second column, as in this example:

      ad    N    1    5    0    0    330    332    0    0
   

   
   c.

   In the same directory, edit the file that corresponds to your new host adapter. Change N to Y in the second column.

   
   d.

   Edit the file /etc/conf/cf.d/mscsi, replacing each instance of the old host adapter driver name (first column) with the new name, as in this example that uses the Adaptec driver, ad:

      *ha     attach  number  ID      lun     bus
      *
      ad      Stp     0       2       0       0
      ad      Sdsk    0       0       0       0
   

   
   

6. Relink your kernel to restore your system configuration using the following commands:
   
   cd /etc/conf/cf.d
   ./link_unix

7. Stop the system:
   
   /etc/haltsys

8. After rebooting your system, restore the backups for your other filesystems on the root disk (if any). Any non-root disks should be accessible after the restore of the root filesystem.