autopath securepath and volume group alternate pvs

[Tiziano Contorno _]

Goodmorning!
We have several paths managed by securepath (11i v2)

This is one of them:
==================================================================
Lun WWN : 0450-2A2A-0451
Load Balancing Policy : Shortest Queue Length
==================================================================
Device Path Status
==================================================================
/dev/dsk/c15t1d2 Active
/dev/dsk/c16t1d2 Active
/dev/dsk/c12t1d2 Active
/dev/dsk/c13t1d2 Active

My question is whenever I have to add the LUN to a VG should I extend it with just one of them or should I need to add each path?

I use only one of them but I found a VG in this machine that has 2 or more path specified (as alternate) in VG pv composition list.

Thank you for your help!
Regards.

[Enrico P.]

Hi,
I know the order of the paths in the VG is important for manual load balancing if you have more than one disk in the vg.
If you are using power path it isn' t important, so you can specify only a path in VG.
Remember that if you export the vg with -s option and import it in the other node you will see all the disks path in the vg of the new node.

Enrico

[Tiziano Contorno _]

Thank you Enrico.

I'm trying to find HP docs about this.

Regards.

[Albert_31]

Securepath will create a new device file as a single path to all the four paths shown above.. you should use that path while in the lvm commands.. and not the individual paths..

check the display command for more infomation..

regards

albert

[Uwe Zessin · Accepted solution]

Here, the "Autopath" component for Active/Active storage arrays is installed, not the 'classic' Secure Path component from the DEC/Compaq world, which supports so-called Active/Passive arrays and creates a single pseudo device.

Autopath does not and there is a customer advisory which suggests you add all existing paths. Otherwise, if only one path was configured and it is missing during a bootstrap, your volume group does not come online.