Veritas DMP (Dynamic Multi Pathing) How to?

[Gene Laoyan]

Has anyone used this?
I have a LUN presented to our Integrity box and it comes up with two disk paths...

/dev/dsk/rdsk/c2t6d0
/dev/dsk/rdsk/c3t6d0

What do I need to do be able to use both paths as one in a failover scenario. From what I have read, using Veritas DMP you can create a disk group and access the disks via the group name. Unfortuneately I have little to no documentation on how to do this.

Any help would be appreciated.

Thanks

[Yang Qin_1]

HPUX got a built-in PVLink with its LVM. PVLink does path failover. What you need to do is that add the second disk paths to the Volume Group with vgextend command. It will be marked as alternate link. When primery link failed, alternate link will become primery link automatically.


Yang

[Alzhy]

Gene,

DMP is only available IF you are fully licensed for VxVM (VxVM Full License).

In your example above, IF you've the full license - once those LUNS/devices are presented -- and after you do "vxdctl enable" - then VxVM will pick the primary path that will appear when you do a "vxdisk list". Usually, VxVM picks the lower "c" or controller number as its primary DMP path.

And you probably already know, but DMP is not just a path protection/multi-pathing scheme. It is a performance enhancer in that it will attempt to always balance the I/Os and use the most efficient paths to your LUNS inside your array...


Cheers.

[Gene Laoyan]

It sounds like something we want to use. How do I check if we are licensed on the system. We have HP-UX MCOE 11.23, what command should I run to check?

What we want to do is to be able to assign an Integrity VM to the disk group to use it as the disk backing.

Where can I get documentaion and examples on how to group 2 of my device files to one device file in a failover scenario?

Thanks

[Alzhy]

vxlicrep

or

vxlicense -p

At 11.23, sepcially the latest OEUR - I believe what HP ships is now VxVM 4.1 so you will probably already find the GUI integrated within SAM...

If not, I can give you a couple samples on working with VxVM.. its really soo easy and simple contrary to 'lore and legend...

[Gene Laoyan]

I would really love to have the samples. I like to know how to do both the GUI and commandline.

BTW, how do I enable it? I grep from a swlist and it does show this...

#swlist | grep -i veritas
Base-VXVM B.04.10.011 Base VERITAS Volume Manager Bundle 4.1 for HP-UX
root@DHAITAN-N3:/
#

Thanks

[Gene Laoyan]

Hmmm....
vxlicrep gives me this...

VERITAS License Manager vxlicrep utility version 3.02.006
Copyright (C) 1996-2004 VERITAS Software Corp. All Rights reserved.

Creating a report on all VERITAS products installed on this system

-----------------***********************-----------------

License Key = 3JZH-CNP6-DP3N-RP40-4HSP-ZNPP-P
Product Name = VERITAS File System
Serial Number = 1
License Type = PERMANENT
OEM ID = 4095

Features :=
HP_OnlineJFS = Enabled

CPU Count = Not Restricted
Platform = HP-UX
Version = 3.5


Does this mean I am not licensed for it?

[Devesh Pant_1]

Is this by any chance an EMC storage?
if yes, EMC has a product called Powerpath that also provides the multipathing that you are looking for.

thanks
DP

[Gene Laoyan]

We are trying to connect to LUN's on our NettApps Filer FAS3020c to our rx8640.

We can see the LUNS and can connect to them but we want some fault tolerance on them.

Thanks

[Alzhy · Accepted solution]

Gene,

I am sorry but it appears you only have the Base VxVM (the built in base license). If you need to have path protection and load balancing to your NetAPP filer, you will need to have the full VxVM license as well as what is called the ASL (Array Support Library) for the array you mentioned (if DMP support is not built in..)


HTH.

[Gene Laoyan]

AWE CRAP!

Thanks for your response. It helped me out immensely.