RAID sets created in Disk Utility when Japanese is the preferred language do not appear in the Mac OS X Server installer. Existing RAID sets cannot be deleted in Disk Utility while Japanese is the preferred language. An alert box may appear with a message indicating that an unexpected error occurred.
Note: This issue only occurs when the Xserve is started up from the Mac OS X Server 10.1.5 CD.
Solution
2. Click the Back button in the installer until you see the language selection screen.
Note: You may have to restart the Xserve if you have proceeded too far in the installer.
3. Select a language other than Japanese.
4. Choose Open Disk Utility from the Installer menu.
5. Create RAID set(s).
6. Quit Disk Utility.
7. Select Japanese.
8. Proceed with installation of Mac OS X Server 10.1.5.