Making Sense Out of Scrambled Eggs, or Re-assembling Humpty Dumpty
by Claus Mikkelsen on May 28, 2009
So I enjoyed the responses on the anagram and there were a lot of correct answers submitted, but unfortunately I failed to mention there was no prize involved. Sorry folks.
But I would like to crisply answer a number of the questions that have come up in the last 36 hours and try to recreate the egg from the scrambles.
Firstly, there is no host requirement, and we support all platforms except z/OS. z/OS has Hyperswap which is very similar to AM when you think about it.
So it’s transparent to the apps which is a very good thing. No agents, no restrictions, no impact on performance (other than that imposed by synchronous replication; we’re used to these kinds of things).
You simply define which LUNs you wish to include (much like you would do with any replication product), the array copies the data over and the LUN is either moved (if this is a migration scenario) or kept in a “mirrored” state, available in case a failover is initiated. So it’s not double the storage or double anything other than what data you wish to move or protect. Again, just like any other replication scenaro. The only additional requirement is that the quorum disk needs to be external to the USP-V.
Keep in mind, this “magic” is done entirely within the embedded software of the USP-V and does not require additional investment other than the quorum disk (keeping in mind that pricing is not finalized).
Availability is Q4, and yes, it has been tested by customers. This announcement is not a slide deck of what sounds cool in the future, nor is it vaporware, this is reality. Sorry guys…
Is AM for everyone? probably not, but the interest I’ve seen from NDA’ing this for a number of months would indicate that interest is a lot higher than some of these blog comments might think (or hope).
There it is, transparent failover from one array to another in the event of loss of access. It’s as simple as that…
Comments (2 )
Techmute on 28 May 2009 at 6:39 pm
OK, few questions -
Any implementation white papers?
Are there zoning requirements, or does the replica take the WWNs of the front end adapters on the primary USP?
In the case of one of the USPs going down hard and immediately, how long does the failover take?
the storage anarchist on 28 May 2009 at 6:48 pm
Hey, I hate to be a pest…but what about the rest of the questions?
Your selective answers seem to underscore the industry’s growing concern that you’re hiding something. Why wasn’t the GA date of Q4 noted in the announcement - at least EMC came out right up front and gave FAST delivery schedules…seems Symmetrix customers could have FAST before Hitachi customers can have HAM.
And you’re saying that there are no host SW requirements whatsoever? If so, please explain to us all exactly how a host knows to start sending I/Os to a different target in the fail-over scenario?
And exactly how does consistency and compliance work when TSM can’t relocate a volume that is being replicated?
Oh, and please - you are the undeniable expert in all things IBM mainframe. Are you suggesting that Hyperswap is the solution to tech refresh migrations for CKD devices?
With all due respect, if indeed there is nothing to hide, then please - answer ALL of my questions - one by one.
And while you’re at it - explain why I had to ask these questions in the first place: why did HDS choose to hide the details in Such An Important Announcement?????
Enquiring Minds wanna know!
