Sense Path Group Id - IBM Multiprise 3000 Reference Manual

Sense Path Group ID

Description: The Sense Path Group ID command transfers 12 bytes of path
group data to the channel. The 12 data bytes are a portion of the addressed
logical volume's path group data associated with the channel path where this
command is executed. Byte 0 contains the path state byte. Bytes 1 through 11
contain the current path group ID for the channel interface.
This command operates even if the logical volume is busy or not ready. See
"Effect of Subsystem and Device State on Status Presented to Command" on
page 2-5 for the operation of this command when other subsystem and device
status conditions occur.
The path-state byte (byte 0) is shown in Table 4-33.
Bytes 1 through 11 contain the current path group ID associated with the
addressed logical volume. If no Set Path Group Identifier currently exists for this
channel path, this field contains 11 bytes of zeros. If a valid ID exists for the
interface, it is in this field. A valid ID may be one that has never been issued to
this particular logical volume, but it was issued to some other logical volume on this
interface and, therefore is the only acceptable ID for this interface.
4-128
Internal Disk Subsystem Reference Guide
Hex Code Data Address
34 The main storage location for the first byte of path group
identification.
Table 4-33. Sense Path Group ID Byte 0 Definition
Byte Value Description
0 Bits
0–1 00 Reset. No Set Path Group ID command has been accepted on this
channel since the last system reset or power-on reset.
01 Reserved
10 Not grouped. A valid path group ID for this channel exists, and the
addressed logical volume does not belong to any group. This state
exists when this logical volume is not grouped or a Set Path Group
Identifier command has been presented on this channel to another
logical volume (but never to this logical volume).
11 Grouped. A valid path group ID exists for this logical volume on this
channel, and the logical volume is shared by a group.
2–3 00 The addressed device is not currently reserved.
01 The addressed device is not currently reserved, but there is a
contingent or implicit allegiance to another member of the channel
group (when a group exists).
10 The device is reserved, but not to this channel.
11 The addressed device is reserved to this channel and to other
members of the channel group when one exists.
4 0 Single-path mode.
1 Multipath mode. Not supported by the Internal Disk Subsystem.
5–7 000 Reserved, set to zeros
Count
12