HPUX and EVA securepath

[Mark Johnson_1]

We have recently purchased an EVA5000 and I am attaching various HPUX systems to it. Almost all of the systems that will utilize EVA disk have a single data path or HBA (they are test systems not designed for fault tolerance). My question is: Is securepath needed, desirable, optional in an HPUX/EVA environment. So far, HP9000 systems attached (zoned) to the EVA get multiple results. Sometimes the systems see one disk, sometimes they see one disk with two paths.

P.S. This thread has been moved from Disk to HP-UX > sysadmin. -HP Forum Moderator

[Ian Vaughan]

Howdy,
I would say that securepath is unfortunately still a necessity for HP-UX. On windows we now have MPIO to handle failover and on Linux we have SteelEye & Qlogic driver multipathing but on HPUX SecurePath is still the only choice.

As the EVA presents each LUN to both controllers and each controller is attached to both (you do have 2?) switches at least 2 versions of the same LUN will turn up even if you only have 1 HBA. It certainly makes things easier if you can only see 1 version of each Vdisk. Compared to how much the 5K cost the Secure Path LTU's are probably reasonable.
How about consolidating the test systems down into fewer boxes? If you have N & L-class systems rp3440's will wipe the floor with them in terms of tpm's and will probably work out cheaper compared with ongoing support costs. Slightly off topic but every little helps...
Cheers
Ian

[Mark Grossman]

Mark,
we run several HPUX L and A class test servers with only 1 HBA fiber card and no secure path software.
We do however hard zone these to only one fiber switch/one eva controller for both directions.
We have had no problems with this scenario.

Mark

[Alzhy]

HP-UX Single HBA connections to EVAs are fully supported by HP and I believe even documented very well.

For your Production Machines though with dual HBAs, you cannot get away without SecurePath if you want fault tolerance and load balancing (on the HBA level at least). Note that PVLINKS is not supported on EVA LUNs. Also note that DMP (in case you plan to use full VxVM) does not also work with EVA paths (yet).

[Mark Johnson_1]

All Ports on the EVA are connected to one fabric. Controller A, port 1 and 2, Controller B, port 1 and 2. So which of the possible four ports do I want my HBA to see (zoned).

[Mark Grossman]

Mark,
pick one - your choice.
We just manually try to balance our single HBA servers, and the port to use to the eva.

Mark

[Mark Johnson_1]

Mark,
How do you assign a disk on the EVA to a port. I understand how to assign a disk to a controller.

Thanks

[Mark Grossman]

Mark,
I guess I'm a little confused now.
Does this look correct?
1) we plug our single HBA into Port 4 of switch 1. Port 1 goes to Cntrl A, and 2 goes to Controller B.
2)we zone it so port 4 only uses port 1 to communicate with the eva only thru port A.
3)we create a vdisk on the eva and present it to the host with this HBA card.
4)we ioscan -fnCdisk and insf -e on the hpux host.
We should now see the disk and the device file and it shouldnt change.

Mark

[Thayanidhi]

Hi Nelson,

Are you sure "PVLINKS is not supported on EVA LUNS" In some places I used PVLINKS over EVA LUNS. So for there is no issues. I installed patches which are recommended for SP, but not installed the SP. Any official document from HP, that the SP is must for EVA LUNs.

Thanks
TT

[Uwe Zessin]

Then you have just been lucky. PVLINKS requires active/active paths to a virtual disk, but that is not a feature of the EVA3000/5000. Have you really, really tested failovers between all 4 paths?

Here is a pointer to an old document, but it is still valid recarding PVLINKS:
http://h18000.www1.hp.com/emea/presalessupport/downloads/EVA_HP-UX.pdf