1 08/28/86  set_drive_usage, sdu
 2 
 3 Syntax as a command:  sdu drive_name usage_type
 4 
 5 
 6 Function: converts a disk drive from storage system use to user
 7 input/output use or vice versa while the system is running.  You can
 8 use it in ring 1 or 4.
 9 
10 
11 Arguments:
12 drive_name
13    is the name of the drive whose use is to be changed.  It has the
14    form <subsys>_<nn>, e.g., dska_05.
15 usage_type
16    can be one of the following:
17    io
18       converts the specified drive to user input/output use.  This
19       drive must be a storage system drive.  The drive cannot have a
20       known or accepted physical volume on it; if one is present, use
21       the del_lv and del_vol commands to remove it before issuing this
22       request.  Once converted, this drive remains a user input/output
23       drive until you issue sdu again.
24 
25 
26    storage_system, ss
27       converts the specified drive to storage system use.  This drive
28       must be a user input/output drive.  The drive cannot be assigned
29       to any process; you can use the rcp command to find out.  You can
30       use the "x deny" command to forcibly remove the drive from any
31       user process to which it may be attached.  Once converted, this
32       drive remains a storage system drive until you issue sdu again.
33 
34 
35 Notes: Drives in use by the storage system appear as "storage system"
36 to rcp, which means that they are unavailable for users.  Drives
37 assigned to user input/output use appear as "(io drive)" to the
38 list_disks command.