&*'78VHUV0DQXDO
For this reason, this host-drive has target-ID 0 and LUN 0. The formula for determining tar-
get ID and LUN from the existing host-drive numbers yields the following possible combi-
nations for "Direct Access Devices":
+RVW'ULYH
QXPEHU
7DUJHW,' /81
+RVW'ULYH
1R
7DUJHW,'
/81
0
0
0
8
1
0
1
0
1
9
1
1
2
0
2
10
1
2
3
0
3
11
1
3
4
0
4
12
1
4
5
0
5
13
1
5
6
0
6
14
1
6
7
0
7
15
1
7
This conversion is necessary because the single SCSI devices are not declared to the host
operating system in the order of their SCSI-IDs, but according to the host-drive numbers of
GDTSETUP. The ICP Controller needs host-drives in order to be able to link several SCSI
devices to form a higher structure (i.e., RAID 5). The sequence of the single host-drives can
be changed very easily by having GDTSETUP sort them in its "Configure Host Drives" menu.
In this way, it is also possible to change the boot drive (it had previously been selected as
boot drive because it has the lowest drive number, that is, 0, and is therefore the first drive
to be communicated to the system ). There is one restriction that has to be observed with
Interactive UNIX: Even though gaps are allowed when numbering the host-drives, if there
are several Host Drives, a certain number for a device having a LUN greater than 0 may only
be selected if this number already exists for another device with LUN 0. In other words, a
certain number can only be assigned to a LUN >0 position if the LUN 0 position has also
been assigned.
