[dm-devel] LVM2 plus device-mapper-multipath filter question

[Phil Lowden (plowden)]

I'm using LVM2 with device-mapper-multipath 0.4.5 on GA RHEL 4 update 2 
release, kernel version 2.6.9-22.ELsmp.  Storage is 4 Clariion CX600
LUNs.

I've got this filter statement in /etc/lvm/lvm.conf:

  filter = [ "a|^/dev/mapper/.*|", "r/.*/" ]
 
and this for types:

  types = [ "device-mapper", 16 ]

I notice any LVM2 commands that show PVs uses the dm-* devices:

# pvs
  PV         VG      Fmt  Attr PSize    PFree  
  /dev/dm-0  vgtest2 lvm2 a-      4.00G   3.90G
  /dev/dm-1  vgtest2 lvm2 a-      3.00G   2.90G
  /dev/dm-2  vgtest2 lvm2 a-      2.00G   1.90G
  /dev/dm-3  vgtest2 lvm2 a-   1020.00M 920.00M

This is true except when /etc/lvm/.cache is brand new:

# rm /etc/lvm/.cache
# pvs
  PV                                            VG      Fmt  Attr PSize
PFree  
  /dev/mapper/3600601604b600d00743e69d8862fda11 vgtest2 lvm2 a-
1020.00M 920.00M
  /dev/mapper/3600601604b600d00753e69d8862fda11 vgtest2 lvm2 a-
2.00G   1.90G
  /dev/mapper/3600601604b600d00763e69d8862fda11 vgtest2 lvm2 a-
3.00G   2.90G
  /dev/mapper/3600601604b600d00773e69d8862fda11 vgtest2 lvm2 a-
4.00G   3.90G
# pvs
  PV         VG      Fmt  Attr PSize    PFree  
  /dev/dm-0  vgtest2 lvm2 a-      4.00G   3.90G
  /dev/dm-1  vgtest2 lvm2 a-      3.00G   2.90G
  /dev/dm-2  vgtest2 lvm2 a-      2.00G   1.90G
  /dev/dm-3  vgtest2 lvm2 a-   1020.00M 920.00M

Here's the /etc/lvm.cache file:

# This file is automatically maintained by lvm.

persistent_filter_cache {
        valid_devices=[
                "/dev/mapper/3600601604b600d00763e69d8862fda11",
                "/dev/mpath/3600601604b600d00773e69d8862fda11",
                "/dev/mapper/3600601604b600d00753e69d8862fda11",
                "/dev/mpath/3600601604b600d00753e69d8862fda11",
                "/dev/mapper/vgtest2-lvstripe1",
                "/dev/vgtest2/lvstripe1",
                "/dev/mapper/3600601604b600d00773e69d8862fda11",
                "/dev/dm-2",
                "/dev/dm-3",
                "/dev/dm-4",
                "/dev/mpath/3600601604b600d00763e69d8862fda11",
                "/dev/dm-1",
                "/dev/mpath/3600601604b600d00743e69d8862fda11",
                "/dev/dm-0",
                "/dev/mapper/3600601604b600d00743e69d8862fda11"
        ]
}

If I remove everything but the /dev/mapper and lvstripe1 entries I get
this:

# pvs
  PV                                            VG      Fmt  Attr PSize
PFree  
  /dev/mapper/3600601604b600d00743e69d8862fda11 vgtest2 lvm2 a-
1020.00M 920.00M
  /dev/mapper/3600601604b600d00753e69d8862fda11 vgtest2 lvm2 a-
2.00G   1.90G
  /dev/mapper/3600601604b600d00763e69d8862fda11 vgtest2 lvm2 a-
3.00G   2.90G
  /dev/mapper/3600601604b600d00773e69d8862fda11 vgtest2 lvm2 a-
4.00G   3.90G
# pvs
  PV                                            VG      Fmt  Attr PSize
PFree  
  /dev/mapper/3600601604b600d00743e69d8862fda11 vgtest2 lvm2 a-
1020.00M 920.00M
  /dev/mapper/3600601604b600d00753e69d8862fda11 vgtest2 lvm2 a-
2.00G   1.90G
  /dev/mapper/3600601604b600d00763e69d8862fda11 vgtest2 lvm2 a-
3.00G   2.90G
  /dev/mapper/3600601604b600d00773e69d8862fda11 vgtest2 lvm2 a-
4.00G   3.90G

Is this just cosmetic?  Is there a config change I can do to make path
listings consistent?  

Thanks in advance,
Phil Lowden