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Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x

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charlie_bulosan
Frequent Advisor

Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x


Hi All,

We have some systems that uses Secure Path (Active-Passive) 3.0F SP2 to access an EVA 3000 with VCS 3.110. I'm investigating whether there is really performance benefit if we move to EVA 3000 vcs 4.x to make it an Active-Active disk array. This will require Secure Path to be reloaded to support an Active-Active disk array and then enable Load Balancing. I've been hearing that there's performance penalty on read when a LUN is accessed through the secondary controller.


Many Thanks,
Charlie
7 REPLIES
Víctor Cespón
Honored Contributor
Solution

Re: Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x

In Active/Active mode, the disk can be accessed though both controllers (all 4 or 8 ports), but each vdisk is owned and handled by only one controller.
When the request comes from the other controller, it passes the request to the owner controller, whick gets the data and passes it back.
If more than 60% of the requests come from the non-owner controller, then the vdisk changes the ownership to that controller.
Securepath can be configured to use all available paths, sending data though the path with the shortest queue or the lowest service time for example.
And finally, the EVA3000 is not really optimized to work in Active/Active mode, it has only one link between controllers and it's in a shared bus with other ports.
charlie_bulosan
Frequent Advisor

Re: Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x

Hi vcespon,

Many thanks for your input.

It seems like for Secure Path with EVA3000, it is better to use the "Low Service Time" for its Load Balancing feature.

This also means that if we remove Secure Path and just use the LVM PV Links method for coarse load balancing, this won't work very well.

Another reason why we are force to upgrade to VCS 4.x is that we are moving to HP-UX 11iv3. 11iv3 does not support Active-Passive disk arrays anymore.


Thanks,
Charlie
charlie_bulosan
Frequent Advisor

Re: Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x


Hi vcespon,

Did you have performance improvement when you upgraded your EVA 3000 to vcs 4.x?



Thanks,
Charlie
Torsten.
Acclaimed Contributor

Re: Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x

Performance or not, if you want to use HP-UX 11.31 you need to upgrade to active/active.

The native multipathing already built-in in the OS denies the use of secure path.

Hope this helps!
Regards
Torsten.

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charlie_bulosan
Frequent Advisor

Re: Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x

Hi Torsten,

First of all we are investigating for the possibility of performance improvement if we move to vcs 4.x which makes the EVA3K an Active-Active (which require Secure Path/Autopath). We will still use 11.23 in this case. Do you think there will be performance improvement?


thanks,
Charlie
Torsten.
Acclaimed Contributor

Re: Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x

Not sure about a performance improvement, but an active/active array does not require secure/autopath. You can use PVLINKS.

See also the autoswitch option in pvchange man page:

http://docs.hp.com/en/B2355-60105/pvchange.1M.html


Hope this helps!
Regards
Torsten.

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charlie_bulosan
Frequent Advisor

Re: Is there performance benefit in Secure Path Active-Active and EVA3000 vcs 4.x

Hi Torsten,

If we use LVM PV links, the -S autoswitch option set to "y" is the default.

---------From the man page ------

-S autoswitch This option specifies the autoswitch behavior for multiported physical volumes accessed via multiple paths. It has no effect for physical volumes without alternate paths. autoswitch option may be set to one of the following values:

y LVM is directed to automatically switch from the path it is using whenever a better path to the physical volume is available. LVM will switch paths when a better path recovers (after it had failed earlier), or if the current path fails and another path is available. This is the default.

n LVM is directed to automatically switch to using the best available path only when the path currently in use is unavailable. LVM will continue using a specific path for the physical volume as long as it works, regardless of whether another better path recovers from a failure.

--------------end ----------------


Since this is the default, do we still need to manually do this for all the disks?


Many Thanks,
charlie