hdisk & hdiskpower

I am going to use EMC disks for AIX systems.    What do hdisk and hdiskpower represent?
IN AIX, we just say hdisk, but with EMC, we have hdisk and hdiskpower.  

thx much
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

hdiskpower is the powerpath device.  Basically it's a virtual device that balances the load across all of the assigned HBAs for that physical device, and provides path failure protection.  You want to use the hdiskpower devices instead of the hdisk devices because otherwise if an HBA went offline, you'd lose access to the devices on that path.  

ethanjohnsonsAuthor Commented:
OK..  When you add PVs to VGs, do you add hdisks or hdiskpowers?  

The reason I am asking is that i.e. hdiskpower1 for hdisk50 and hdisk5.  I assume that you need to hdisks to VGs.

thx much

Pseudo name=hdiskpower1
Symmetrix ID=xxxxxxxxxxx
Logical device ID=020C
state=alive; policy=SymmOpt; priority=0; queued-IOs=0
---------------- Host ---------------   - Stor -   -- I/O Path -  -- Stats ---
###  HW Path                I/O Paths    Interf.   Mode    State  Q-IOs Errors
   1 fscsi1                    hdisk50   FA 10cB   active  alive      0      0
   0 fscsi0                    hdisk5    FA  7cB   active  alive      0      0
You should use the hdiskpower devices, otherwise you'll have problems if one path goes down.  

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.