Mobility and Availability Go Xtrem

Have you recently heard about this new all flash array from EMC? Might have gone past your RSS feeds, your twitter timelines, your blog rolls and your press release markers.


Of course I am kidding. Unless you have been hiding under a rock or data storage is not a meaningful technology category for you, you could not possibly have missed the tremendous launch that XtremIO just had. On second thoughts, even if you were hiding under a rock, the EMC marketing team would have found a way to get to you. The reception from customers, partners and competitors to the XtremIO launch has been overwhelming. Customers have been raving about the XtremIO technology, partners are excited to sell XtremIO. Competitors – well, let’s just say that it has been interesting to say the least – there were twitter feuds, ad wars, positioning conversations, good natured ribbing and some downright FUD. And so I am above board, I am sure we have done our fair share of all of the above. Keeps life fun and interesting in the tech space for all of us.
Itzik covers XtremIO in all its gory glory in his blog posts
All of these are highly recommended reads if you want to learn about XtremIO.
For my part, I will focus this blog on the intersection between VPLEX and XtremIO. I am already seeing a ton of interest in our customer base and our field for this combination. Part of my focus is going to be to clarify what use-cases we are seeing customers use VPLEX in front of XtremIO for as well as to answer some of the questions we are getting.

Use Cases for XtremIO and VPLEX

Load balancing / Operational Flexibility

This is one we have seen a lot of customers use VPLEX with XtremIO for.
I will be the first one to admit – there are customers who put all their workloads on all flash arrays and there are customers that do not. If you are in the first category, this use-case does not apply that much to you. If you are in the second bucket (which is the overwhelming majority of the customers I talk to) then, you are deploying some of your workloads on all flash arrays and most on hybrid or non-flash arrays. In this mode, customers have workloads that belong on flash but not all the time. In other words, they have workloads that are temporarily resident on flash before moving back to the hybrid array tiers. In other words, these workloads have a temporal performance need. Because of this, customers put VPLEX in front of XtremIO combined with other arrays (we OBVIOUSLY love it when these other arrays are VMAX/VNX but they do not have to be). The workload largely resides on the non-all-flash-array and then moves to the all-flash array temporarily and then is moved back to the non-all-flash array once the associated performance need diminishes. We typically see this with IT shops that operate on storage charge back models based on SLAs. This way, the charge back costs are kept as low as possible.

Cross Array Availability

This use-case is certainly not unique to all flash arrays by any means. However, customers are increasingly using VPLEX as a cross array data protection tool. The value of doing this is that if you happen to need downtime on one array (either planned or unplanned), then with VPLEX you can mirror volumes across two arrays and in that way accomplish a higher level of protection. With flash arrays, we see customers typically protect between multiple flash arrays. An interesting variant of this use-case is where customers are deploying VPLEX Metro within the data center and are using cross array availability as a means to protect across two entirely different failure domains within the same data center (e.g. two fire cells, two different floors). One note of caution for customers: Since the protection mirrors in this case (RAID-1s) are synchronous mirrors, for flash array customers especially, it is worth remembering that the latency of your I/O will be the slowest array that is a part of the R1 volume map. Given this, it is beneficial for the arrays forming the R1 legs to have similar latency characteristics. In the case of all flash arrays, this means that the typical flash R1, all legs should be all flash.

Non-disruptive Tech Refresh

Another big use-case that we hear from customers in the all-flash-array space is future flexibility. A lot of the all flash array platforms are continuing to evolve rapidly with newer versions being available sooner rather than later. This has implied that customers have felt the need to future proof themselves and enable migrations to those newer platforms more seamlessly. VPLEX because of its ability to migrate non-disruptively (Does VPLEX do migrations?) becomes a logical choice for customers looking for this option. The same also applies for customers who anticipate their future flash needs growing. VPLEX provides a means to present and aggregate flash storage.

Long distance DR protection with RecoverPoint

Here is a two-fer. With the RecoverPoint splitter in-built into the VPLEX platform, it can be used for DR protection for XtremIO. Given the heterogeneous support of VPLEX and RecoverPoint, you can copy the DR protection leg to any EMC or non-EMC array. RecoverPoint will also give you continuous data protection in addition to the continuous remote replication. This means that a combination of VPLEX and RecoverPoint will give you HA and DR in combination with XtremIO.

On boarding

Another form of migration – this one to move data onto the flash array. Too often customers have more than one array type and are looking to move a portion of their workload from those disparate array onto XtremIO. Traditionally, this would mean figuring out a way to copy the data over (which is likely different between every combination of arrays). Putting VPLEX in front of the non flash arrays as well as XtremIO, will enable a seamless and a uniform migration experience between the source array (any one of the 45+ EMC and non-EMC arrays that are supported by VPLEX) and XtremIO. By the way, if you are moving lock stock and barrel to XtremIO from existing arrays, you can use the free 180 day VPLEX Migration license (described here) available with the purchase of a new EMC array.

Heterogeneous Host connectivity

Another relative freebie – While I do not foresee this as being the primary reason to put a VPLEX in front of an XtremIO, because of the vast host side interoperability that has been built over the years with VPLEX, you get host connectivity for all the hosts supported by VPLEX in VPLEX Support Matrix (AIX and HPUX anyone?). I am sure over time XtremIO will build this support natively. Until then, this can tide you over if you happen to have hosts and clustering infrastructure that is not on the XtremIO support matrix.
Josh Goldstein, VP of Product Management/Marketing for the XtremIO team does an exceptional job describing the interplay between XtremIO and VPLEX here.

Questions we have seen thus far

What latency does VPLEX add to my all flash workloads?

The most direct answer to this question is that it depends.
However, the real question behind the question is ‘Am I lose the benefit of the latency reduction I got from my purchase of XtremIO?’. Again, the straight answer is that VPLEX will add latency to the mix. So, the combination of VPLEX and XtremIO will, for most workloads (non read cache hit intensive) have higher latency than XtremIO alone. So, if you have workloads that need the absolute latency of XtremIO, then you should direct connect to XtremIO. However, these workloads are far and few in between. If you are a typical customer with a typical workload, the more appropriate compare is the latency incurred with a non-all-flash-arrays. Here, for most workloads, VPLEX + XtremIO will come out ahead in terms of total latency. Now, the real answer will depend on the latency that your application needs, your workload mix and the use-cases that are important to you from the list above. And from there, it becomes conversation about the relative priorities between them which will help you understand which workloads are suited for the VPLEX/XtremIO combination.
As we get more questions, I will post them to this blog. If you are a VPLEX/XtremIO customer, we would love to hear from you!

About the Author: Ashish Palekar