Subject: Re: 64-bit LUN support
To: Bill Studenmund <>
From: Eduardo Horvath <>
List: tech-kern
Date: 01/07/2005 18:45:31
On Fri, Jan 07, 2005 at 10:34:15AM -0800, Bill Studenmund wrote:

> 64-bit LUNs are hierarchical. They consist of 4 16-bit values. "Normal" 

Don't count on it.  LUN format is application dependent.  There are
at least two example implementations in the standards documetnation
which use the bits quite differently.  And I'm aware of some others.

Unless you can be sure that a device uses a particular LUN format
it's best to consider them to be opaque cookies.  LUN values can
change as a device changes state or is reconfigured (ISTR there's
a unit attention condition associated w/that).