Chapter 9. Administration - Logical Tab  245
Draft Document for Review March 28, 2011 12:24 pm 7914Admin_Logical.fm
ň° media scan
ň° media scan with redundancy check
ň° pre-read redundancy check
You can also set your regular Logical Drive as source of advanced copy services, like 
FlashCopy, VolumeCopy or Enhanced Remote Mirroring in the Logical pane (Figure 9-24 on 
page 244). These functionality are described in IBM Midrange System Storage Copy 
Services Guide, SG24-7822.
To start with configuration of the Logical Drive, select the Logical Drive you want to modify in 
the Logical pane tree, and right-click. The menu starts with View Associated Physical 
Components. It is the same as if you select the link on second line of the Properties pane. It 
will open a window to display the components associated with the Logical Drive like the disk 
drives, location of the drives, the controller, the controller which currently owns selected the 
Logical Drive. These physical components are marked by blue bullet.
The second option in the menu is Change. Using this option, you can modify all important 
parameters of the Logical Drive. Select this line and next menu opens as in Figure 9-25.
Figure 9-25   Logical Drive - Change menu
We describe all possible changes of a Logical Drive parameters in the following sections:
ň° 9.5.1, âChange Modification Priorityâ on page 245
ň° 9.5.2, âChange Cache Settingsâ on page 247
ň° 9.5.3, âChange Media Scan Settingsâ on page 250
ň° 9.5.4, âChange Pre-Read Redundancy Checkâ on page 252
ň° 9.5.5, âChange Ownership/Preferred Pathâ on page 253
ň° 9.5.6, âChange Segment Sizeâ on page 254
9.5.1  Change Modification Priority
The Modification Priority defines how much processing time is allocated for operations 
modifying the logical drive relative to the system performance. Operations that cause a logical 
drive modification are:
ň° Initializing a logical drive
ň° Reconstructing after a disk failure
ň° Copying back from a hot spare drive
ň° Changing the segment size of a logical drive
ň° Expanding a logical drive
ň° Adding free capacity to an array
ň° Defragmenting an array
ň° Changing the RAID level of an array