2 messages, 2 authors, 2002-10-21 · open the first message on its own page
From: MShetty <hidden>
Date: 2002-10-21 15:58:00
Hi, What exactly is the value of 'target id' when my lun spans multiple disks ?? I am not able to understand how the physical disk address would be obtained when a lun spans multiple disks Thanks and Regards, M Shetty
From: Doug Ledford <hidden>
Date: 2002-10-21 16:31:38
On Mon, Oct 21, 2002 at 09:28:00PM +0530, MShetty wrote:
Hi, What exactly is the value of 'target id' when my lun spans multiple disks ?? I am not able to understand how the physical disk address would be obtained when a lun spans multiple disks
If you are using an external drive chassis that turns multiple disks into
a single lun, then the target id is whatever the target id for the lun is.
The drives that are actually behind the logical lun are *never* exposed to
the scsi layer. If you are talking about using the md raid code to map
several disks into a single md device, then it's the job of the md code to
remap all incoming requests to point to the proper hard disk, and in the
process of doing so it rewrites the target id, the lun, and the block
address to the correct values for the underlying physical disk.
--
Doug Ledford [off-list ref] 919-754-3700 x44233
Red Hat, Inc.
1801 Varsity Dr.
Raleigh, NC 27606