PVlinks on EVA4k/6k/8k

[Mohanasundaram_1]

I am re-opening this thread with replies from Pat and Uwe.

Pat,

As Uwe indicated, the load balance comes as an add-on with securepath. Also, I can do a static load balance (may not be a perfect balance, but can still distribute LUNs on different controllers) using the pv links.

My effort has been to find out the pros and cons of taking either approach and to know the experience of people who started using pvlinks.

As already indicated by me, the cost factor is very much against Securepath and I was under the impression there should be some features which may offset this.

So far I have not heard any major pointers on that. So I would presume more and more customers may like to opt for pvlinks.

This also brings to another question, I understand from VCS 4.0 the EVA5000 will also have active/active controllers. Does that mean PVlink will be supported there too?

The plot thickens.....

WIth regards,
Mohan.

[Uwe Zessin]

It's my understanding that PVlinks is supported on EVA3000/5000 with VCS V4.

[Mohanasundaram_1]

Hi Uwe,

I am really getting confused with this new Active/Active controllers and the need for securepath there.

Even with securepath, the active/active array shows 4 paths for each LUN. So how does one configure the Volume groups (which device to use).

The Securepath install and reference manual indicates a SAN boot LUN configuration option with securepath at page 128,

http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00248499/c00248499.pdf

In that example the vg is extended with the alternate devices, much like the pvlinks. So what does Securepath provide? I am sure the LVM configuration will be same without securepath.

I have been running around with this question for the past 2 days and the more I dig, the more conflicting/confusing information is coming out.

I would appreciate if somebody can share their experience of configuring an EVA active/active array with securepath 3.0F.

With regards,
Mohan.

[Zinky]

We have EVA5Ks which are still running VCS 3.X -- so we still cannot use PVLINKS or ACTIVE/ACTIVE fashion of using the controllers/paths. However, I am confused by earlier pronouncements saying that under VCS 4 or w/ EVA4/6/8K and SecurePath, the disks are presented with 4 accessible devices? With our EVA 5K + SecurePath 3.0E - only one device is accessible - the 4 subpath devices are not configurable as PVLINKs. And already -- I see this as a huge advantage w/ SecurePath. You need not worry about those "other disk devices pointing to the same Vdisk" - as you simply do not see them.

I thought that on EVA4/6/8K and EVA3/5K (w/ VCS 4.x) - SecurePath is already optional since PVLINKS or AP actually work. Additionally, VxVM's DMP is supposedly happy as well with the presentations and works perfectly (although no official support notice from Veritas is available). If this is indeed true, then I would say - for VxVM, just use DMP. But for LVM usage, I will still prefer to use SecurePath IF it's functionality remains the same -- that is it presents only one usable (but path-protected)disk device to the OS.

[Uwe Zessin]

> thought that on EVA4/6/8K and EVA3/5K (w/ VCS 4.x)
> - SecurePath is already optional since PVLINKS

> or AP actually work.

Nelson, AutoPath (AP) _is_ used for Active/Active EVA controllers. AP became bundled with the old SecurePath for Active/Passive controllers to the current Secure Path product.

[Zinky]

Uwe, I thought SecurePath for HSX arrays (the old SecurePath that I am more familiar with) is still the same SecurePath that deals with EVA44/6/8K and that SecurePath for VA (a.k.a. HP AutoPath priduct) still was relegated to VA types and XP arrays. I was aware that since SecurePath 3.0C (or 3.0D) on HP-UX, AutoPath was renamed SecurePath for VA and XP Arrays...

If this is is the case, then AutoPath is totally useless -- specially if you're runing VxVM with DMP enabled (meaning you have full VxVM License).

IF Securepath for HSX arrays is indeed the one actively used for EVA4/6/8K -- then I will sitll go for SeurePath.

[Uwe Zessin]

Secure Path V3.0F is a bundle of the old Secure Path "for HSX" and AutoPath. This AutoPath has been enhanced to include support for "Active/Active" HSV controllers.

If you have an EVA4000/6000/8000, then you install the AutoPath component from Secure Path V3.0F.

If you have an EVA3000/5000 with VCS V4, then you need Secure Path V3.0F service pack 1.

[Zinky]

So Messr Uwe, you're saying that SecurePath for HSX arrays is now dead if you have EVA4/6/8K OR if you've VCS 4.X on EVA3K/5K?

And you're option for path protection (and load balancing) is simply via VxVM DMP, PVLinks or the AutoPath software which is now part of SecurePath?

Is SecurePath for HSX Arrays still an option during an install/upgrade on SecurePath 3.0F release?

[Uwe Zessin]

- I would not call it 'dead', just non-efficient as it does not recognize HSV101, HSV111, HSV200, HSV210 controllers ;-)

- yes

- yes

[Zinky]

We're at SecurePath 3.0E. We have EVA5Ks at VCS 3.020 and we're staying put with that release.

We also have a big XP12K BUT we do not use SecurePath for VA (a.k.a. AutoPath) - we simply use VxVM's DMP.

EVA5K w/ SecurePath for HSX as Path Protection works alongside XP12K in a VxVM DMP environment.