[Bug 224963] GEOM: devices with distinct data should have distinct physical paths

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=224963

            Bug ID: 224963
           Summary: GEOM: devices with distinct data should have distinct
                    physical paths
           Product: Base System
           Version: CURRENT
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Some People
          Priority: ---
         Component: kern
          Assignee: freebsd-bugs at FreeBSD.org
          Reporter: asomers at FreeBSD.org

A device's physical path describes its physical location, as distinct from its
logical or electrical location.  Currently only ses(4) provides physical paths
to da(4) disks, and only zfsd(8) consumes them.  All current GEOM transforms
either present blank physical paths, or pass through the underlying provider's
physical paths.  This is a problem for zfsd(8), because da0, da0p1, and
da0p1.eli will all have the same physical path, so zfsd(8) doesn't know which
to use in an autoreplace operation.

I propose the following two rules for all disk-like devices:

1) The physical path should only be nonempty for providers that have a distinct
physical location.  For example, memory disks, mirrored pairs, and iSCSI LUNs
should not have physical paths.

2) No two providers should have identical physical paths unless they both
provide exactly the same data.  Many GEOM transforms currently violate this
rule, for example geli and gpart.  gsched is an unusual exception, because both
X and X.sched do provide exactly the same data.

-- 
You are receiving this mail because:
You are the assignee for the bug.