LVM mirror with PVG Strict Distributed by MC/SG

[Thomas Stuetzer]

Hello,

thank you for the explanation. Now I have understood the lvm mirror is ok( I should read the mirror in line not in column!).
My aim is to set up a mirror from from storage system A to storage system B. The hardware pfad from device c4 in PVG VA_RZ match with storage system A and and hardware pfad from device c6 in PVG VA_ARZ match with storage system B.
So want to setup a mirror like this:
--- Logical extents ---
LE PV1 PE1 Status 1 PV2 PE2 Status 2
00000 /dev/dsk/c4t1d2 00005 current /dev/dsk/c6t1d2 00008 current
00001 /dev/dsk/c4t1d3 00010 current /dev/dsk/c6t1d3 00007 current
00002 /dev/dsk/c4t1d2 00006 current /dev/dsk/c6t1d2 00009 current
00003 /dev/dsk/c4t1d3 00011 current /dev/dsk/c6t1d3 00008 current

This is done with
lvreduce -m 0 /dev/vgtest/lvb1 /dev/dsk/c6t1d3 /dev/dsk/c6t1d2
lvextend -m 1 /dev/vgtest/lvb1 VA_RZ VA_ARZ

After I deactivate the volume group and activate the volume group the picture is like this:
--- Logical extents ---
LE PV1 PE1 Status 1 PV2 PE2 Status 2
00000 /dev/dsk/c6t1d2 00008 current /dev/dsk/c4t1d2 00005 current
00001 /dev/dsk/c4t1d3 00010 current /dev/dsk/c6t1d3 00007 current
00002 /dev/dsk/c6t1d2 00009 current /dev/dsk/c4t1d2 00006 current
What is the reason for this change?

Here are the volume group
--- Volume groups ---
VG Name /dev/vgtest
VG Write Access read/write
VG Status available, exclusive
Max LV 255
Cur LV 3
Open LV 3
Max PV 16
Cur PV 4
Act PV 4
Max PE per PV 1016
VGDA 8
PE Size (Mbytes) 4
Total PE 508
Alloc PE 60
Free PE 448
Total PVG 2
Total Spare PVs 0
Total Spare PVs in use 0
--- Logical volumes ---
LV Name /dev/vgtest/lvd1
LV Status available/syncd
LV Size (Mbytes) 40
Current LE 10
Allocated PE 20
Used PV 4

LV Name /dev/vgtest/lva1
LV Status available/syncd
LV Size (Mbytes) 20
Current LE 5
Allocated PE 10
Used PV 4
LV Name /dev/vgtest/lvb1
LV Status available/syncd
LV Size (Mbytes) 60
Current LE 15
Allocated PE 30
Used PV 4


--- Physical volumes ---
PV Name /dev/dsk/c4t1d2
PV Status available
Total PE 127
Free PE 111
Autoswitch On

PV Name /dev/dsk/c4t1d3
PV Status available
Total PE 127
Free PE 113
Autoswitch On
PV Name /dev/dsk/c6t1d2
PV Status available
Total PE 127
Free PE 111
Autoswitch On

PV Name /dev/dsk/c6t1d3
PV Status available
Total PE 127
Free PE 113
Autoswitch On


--- Physical volume groups ---
PVG Name VA_RZ
PV Name /dev/dsk/c4t1d2
PV Name /dev/dsk/c4t1d3

PVG Name VA_ARZ
PV Name /dev/dsk/c6t1d2
PV Name /dev/dsk/c6t1d3

[Patrice Le Guyader]

Hello Thomas,

Did you still have the order of disks in vgcreate command when you've made you vg ?

Can you post an extract of ioscan with disks?

kenavo
Pat

[Torsten.]

The reason could be your command

lvextend -m 1 /dev/vgtest/lvb1 VA_RZ VA_ARZ

instead of only

lvextend -m 1 /dev/vgtest/lvb1

Perhaps you can test this.

Anyway, the result looks good as it is and will give high performance.

[Thomas Stuetzer]

Hello Pat,
no, I haven't the order of disk for the vgcreate command.
the ioscan show this:

sapr3man:/etc/cmcluster/pkgtest1#ioscan -fnkH0/4/0/0.2.16.39.0.1
Class I H/W Path Driver S/W State H/W Type Description
=========================================================================
target 9 0/4/0/0.2.16.39.0.1 tgt CLAIMED DEVICE
disk 8 0/4/0/0.2.16.39.0.1.2 sdisk CLAIMED DEVICE HP A6189A
/dev/dsk/c4t1d2 /dev/rdsk/c4t1d2
disk 9 0/4/0/0.2.16.39.0.1.3 sdisk CLAIMED DEVICE HP A6189A
/dev/dsk/c4t1d3 /dev/rdsk/c4t1d3
sapr3man:/etc/cmcluster/pkgtest1#ioscan -fnkH0/4/0/0.2.17.39.0.1
Class I H/W Path Driver S/W State H/W Type Description
=========================================================================
target 13 0/4/0/0.2.17.39.0.1 tgt CLAIMED DEVICE
disk 6 0/4/0/0.2.17.39.0.1.2 sdisk CLAIMED DEVICE HP A6189A
/dev/dsk/c6t1d2 /dev/rdsk/c6t1d2
disk 7 0/4/0/0.2.17.39.0.1.3 sdisk CLAIMED DEVICE HP A6189A
/dev/dsk/c6t1d3 /dev/rdsk/c6t1d3

[Thomas Stuetzer]

The mirror is ok. It was may fault to compare the left side with the right side of the output from lvdisplay -v section
--- Logical extents ---

the command lvextend -m 1 /dev/vgtest/lvb1
give the same result as before. The output of lvdisplay is changed after deactivated and activated the VG again.