Disks often fail in systems and need to be replaced. If you are using solaris and zfs as your file system you will need to offline the bad disk then detach it from your zpool. Once detached you are fine to replace the failed drive. When you replace a disk in the system you will need to scan for the new disk. A command you can use to accomplish this is devfsadm. Simply execute it as follows:
This will perform a complete scan of dev devices and detect the new drive you put in. Once detected you can add it to your storage pool. This tool is another one of the reasons why solaris 10 is a good choice for fantastic file system management.