HP-UX 11i v3 and Hitachi Adaptable Modular Storage 500

[Andrey Chipalyuk]

Hello!

We have used the AMS500 Storage System (Hitachi TagmaStore Adaptable Modular Storage 500).
I want to use AMS500 Storage System for HP Integrity Servers with HP-UX Operation Systems.
I learnt the next documents:

Hitachi TagmaStore Adaptable Modular Storage and Workgroup Modular Storage HP-UX Host Installation Guide.
Hitachi Dynamic Link Manager Software User’s Guide for HP-UX Systems.
HP-UX 11i v3 Native Multi-Pathing for Mass Storage.

I can't find Hitachi AMS500 support the HP-UX 11i v3.
The "HP-UX Host Installation Guide" tell:

2.1 Configuration Requirements
The requirements for undertaking an Adaptable Modular Storage HP-UX configuration are:
...
* HP 9000/800 series system
...
* HP-UX operating system version 10.20, 11.0, or 11i
...
* High-availability (HA) software (optional)
...
– Hitachi Dynamic Link Manager™ for path failover

The "Dynamic Link Manager Software User’s Guide for HP-UX" tell HDLM support HP-UX 11i V1 and HP-UX 11i V2.

The "HP-UX 11i v3 Native Multi-Pathing for Mass Storage" tell:

Active-passive arrays are supported if any of the following conditions is true:
• The vendor has developed and provided an Active/Passive Switch (APSW) plug-in module on HP-UX 11i v3. Refer to the “Writing Active/Passive Switch Plug-Ins” white paper for more information.
• The disk array supports the T10 Asymmetric Logical Unit Access (ALUA) standard. Refer to SPC-3 Section 5.8 for more information.
• The disk array is now active-active symmetric and no loss of performance will occur on a host performing multi-path load balancing simultaneously via different paths to the same LUN.
• The LUN or disk array is connected to a single host OS instance, the load_bal_policy attribute is set to preferred_path or pref_tport, and the array is in auto-trespass mode.

I can't find support AMS500 documents for HP-UX 11i v3.
Do you know AMS500 possible use for HP-UX 11i v3?
Have you any documents about it?

[Michal Kapalka (mikap)]

hi,

you could ask also directly on HITACHI forum.

http://forums.hds.com/

mikap

[Andrey Chipalyuk]

Thank you!
I shall try to ask directly HDS forum.

I found from HDS site Product Interoperability matrix.
HP-UX 11i v3 supports AMS family systems.

I can't find how must I setup HP-UX 11i v3 and AMS System?

[Michal Kapalka (mikap)]

hi,

probably you have found this docu :

http://www.hds.com/assets/pdf/all-models-of-ams-wms-for-hpux.pdf

i don't have any personal experiences with this HDS Storage AMS system.

We installed HDS USP-V = HP XP24000.

mikap

[Andrey Chipalyuk]

Yes, I have yet read the "all-models-of-ams-wms-for-hpux.pdf" document.
This document confirm that HP-UX 11i v3 supports AMS family systems.

Yes, I know that HP XP = Hitachi USP Systems.

[kirkkak · Accepted solution]

We are using 11v2 and 11v3 with AMS500's, last time i checked the native load balance of 11v3 does not work correctly against AMS500.
All paths are seen as active (no ALUA) - and on worst case you may see higher load on storage cpu's cause of using non-default controller.
OR you set preferred path manually (scsimgr set_attr) and everything works :)

[Andrey Chipalyuk]

I careful read the latest document "Hitachi Modular Host Installation Guide for Fibre Channel" (MK-08DF8189-08, May 2010).
This document describes settings of HP-UX and particularly gives some comments for HP-UX 11i v3.
If I correctly understood then AMS option Alternate Path is different for HP-UX 11i v2 and HP-UX 11i v3.
For HP-UX 11i v3 this option must not be specified.
The HP-UX 11i v3 has native multipathing and it don't use HDLM or PVLink settings therefore.

Excuse me, how did you check the native load balance?
When we set a logical unit we must select Default Controller.
Do you think that load balance don't work therefore?
I can't find documents describe load balancing or Active/Active settings for HP-UX on AMS Systems.

[Andrey Chipalyuk]

For load balancing Hitachi Knowledge Base tell next solution:

How load balancing works using HDLM with DF products
On Linux and other open systems OS's with HDLM, you can have multi pathing.
However, you can not load balance across controllers on the DF Products.
The problem is a limitation within the DF products (9200/9500).
The DF products have the concept of LUN Ownership,
You can not perform multi pathing across controllers.
You CAN, however, have 2 paths to the same controller to luns owned by that controller.
Then HDLM will load balance across those 2 paths.
If you wished to take advantage of the non-owning controller, the preferred configuration would be to take luns owned by CTL0 and CTL1 and then use the Linux Logical volume manager [ LVM ] to create a disk that is stripped.
Then use dual paths to one controller when writing to that disk, and HDLM will load balance across those controllers, and the data will be striped across the disk on CTL0 and CTL1.
The true alternative to this configuration is really to get a RAID series where you can load balance down to separate paths.

[kirkkak]

Check the disk configuration from host:
scsimgr lun_map -D /dev/rdisk/diskxx

If you have mapped disk over all four FE ports you'll see that despite active/passive storage all lunpaths are active and LB roundrobin is no good.

So you have to set LB policy to preferred path
# scsimgr set_attr -D /dev/rdisk/diskXX -a load_bal_policy=preferred_path -a preferred_path=lunpathYY or full hw path

and save it # scsimgr save_attr -D /dev/rdisk/diskXX -a load_bal_policy=preferred_path -a preferred_path=lunpathYY

[Andrey Chipalyuk]

Thank!