DMP on Base-VXVM

[Karsten Radke_1]

Hello colleagues,

i need to create a 2.5 TB filesystem on a UX11.23 system with SAN disks. The storage box is a midrange-class HDS 9500 whose LUNs are visible and accessible thru 2 FC HBAs.

I've recently learned that creating a VxFS filesystem larger than 2 TB on LVM volumes is not possible/unsupported on 11.23. According to HP support, i need to use VxVM for this. So far, so good.

The server has the Base-VXVM product ("Base VERITAS Volume Manager Bundle 4.1 for HP-UX") already installed and also set-up. We did not purchase any additional VxVM licenses.
What i need to know is whether the DMP failover feature is already available with the Base-VXVM product without any additional license. I don't want to do any loadbalancing (the HDS9500 is an active-passive array), just a redundant failover.

Many thanks in advance,
Karsten

[Sameer_Nirmal]

No, you would need "full" VxVM license.

http://docs.hp.com/en/5991-5288/5991-5288.pdf

[Duncan Edmonstone]

Karsten,

DMP is *not* part of the base VxVM product I'm afraid.

However I suspect the response centre are giving you out of date information. You can now create LVs up to 16TB in size in LVM on 11.23 see the table on p3 of the technical paper here:

http://docs.hp.com/en/6054/LVM_Limits_White_Paper_V4.pdf

Note that the patches mentioned as needed to enable 16TB LV support have been superseded in some cases now.

If you still have the call open with support, you should point the engineer in question at this - making this sort of mistake once is excusable, but it needs fixing.

HTH

Duncan

[Karsten Radke_1]

Duncan,

indeed the support case with HP is still open. I will contact the engineer again and point out what you have remarked here. I have been aware beforehand that the LVM limits have been increased starting with 11.23, but my problem was that mkfs failed on the 2.5T lvol.

Anyway, this is a very good hint, and i will try to clear this with HP.


many regards,
Karsten

[Duncan Edmonstone]

Karsten,

What version of VxFS do you have installed? Early versions of 11.23 only had VxFS3.5 which only went up to 2TB filesystems...

There's a similar table for supported filesystem sizes here:

http://docs.hp.com/en/5992-4023/5992-4023.pdf

See p3

HTH

Duncan

[Karsten Radke_1]

Duncan,

according to swlist i apparently have VxFS 4.1 installed:

Base-VXFS 4.1.002 VERITAS File System Bundle 4.1 for HP-UX

I also have OnlineJFS installed, but what is confusing me somehow is that "vxlicrep" shows "3.5" as the version number:

krethi:/root# vxlicrep

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

Is there possibly any mismatch between the versions of OnlineJFS and the Base-VXFS??? I suppose not.

[Karsten Radke_1]

While browsing thru HP's knowledge base, i've found emr_na-c01005587-2 ("You don't need VxVM Full product to use EMC PowerPath") which states the following:
"For the base VxVM product, DMP with path failover is provided with
Active/Passive arrays but not Active/Active arrays. "

That might be exactly what i need to know. However, i will check this out with HP support, just to be sure.

[Alzhy]

Shalom.

Your path with VxVM will not work as the HDS 9500 (aka Thunder arrays) require a special ASL (array support Library) under VxVM 4.1 to enable PATH preotection to your ALUA (assymetric active/active) storage array. And the sad part of it all.. the ASL will only kick in (DMP) if you have a Full VxVM License.

Your option:
1. Upgrade to HP-UX 11.31 if you can where there is a workaround to the Thunder ALUA arrays and where you can use either LVM or VxVM.

2. Buy VxVM License


Sorry.