XtremIO: Extreme Performance, Unmatched Storage Efficiency!

Companies are quite comfortable adopting snapshots as a tool for data protection. Yet "replication" of environments with ultra-intensive operations, such as all-flash arrays, can be a real challenge … or as Blade Runner would say either a benefit or a hazard!

We are drowning in data. In every company, every sector and every country data volumes are constantly growing. Yet paradoxically, although there is much talk about the difficulties of managing these astronomic quantities of information, organisations need more than ever to replicate their data.

“Replication is like any other machine. Either a benefit or a hazard …”

There are two main reasons for this: the first is the need to constantly innovate. New applications and new systems are regularly put in place by IT teams to best serve business needs. To do this, they need to be able to work on test environments identical to the production environments, and which are therefore replicated.

The second reason relates to the criticality of the information system in the digital world of today. Data losses can prove dramatic for organisations that are victims of them, and replication provides vital protection. However, not all replication is equal.

The Cost/RPO Balance – “Replicants are like any other machine. They′re either a benefit or a hazard. If they are a benefit it′s not my problem.”

Replicating an environment will always bring a certain number of problems. Lots of companies are forced to tread a thin line, to strike the right balance between RPO (Recovery Point Objective, or maximum admissible target period for data loss) and costs.

The more critical the data, the more the company will be keen on replicating them as frequently as possible. In this way, if there is a problem, the quantity of data loss will be minimal and the impact on business minor. Yet bringing down the RPO automatically involves increasing the costs. Systems will need higher performance and greater bandwidth.

The problem is further exacerbated with the new generations of powerful intensive I/O all-flash arrays, such as those proposed by Dell EMC with its XtremIO range. How do we put in place an efficient replication process when faced with environments capable of executing several hundreds of thousands of IOPS? The solution is to be found in the metadata.

More Metadata, Less Data – “If only you could see what I′ve seen with your eyes!”

Version 6.1 of the XIOS operating system, shipped with all XtremIO arrays, heralds a new way of protecting data, called "metadata-aware replication". The traditional solutions based on snapshot or streaming mechanisms replicate to the secondary infrastructure any change made to the primary infrastructure. XtremIO X2 arrays propose a different approach. Each data block written to the platform is allocated an identifier, stored in the form of metadata. When the identifier is unique, the block is physically replicated. However, when the identifier is already known, only the metadata is stored together with a pointer to the already-existing block, as illustrated in the figure below:

What are the benefits of this? Firstly, the process reduces the bandwidth requirements by 75%. Next, compression and deduplication enable the space required on the backup site to be reduced by 38%. These are two benefits that have a direct impact on protection costs. Lastly, the fact of having less data transiting over the network and to be written to the secondary media accelerates replication and therefore brings down the RPO to 30 seconds for the most critical workloads. XtremIO X2 arrays are also capable of managing up to 500 restore points. This is ideal for test and development environments on which many modifications have to be made.

Availability: Goodbye to RAID, Hello to XDP – “The light that burns twice as bright burns half as long. And you have burned so very, very brightly!”

The protection of a flash array also needs to be adapted to the specific characteristics of its storage media. IT teams traditionally put in place RAID mechanisms, which present drawbacks specific to the use of mechanical media. Depending on the type of RAID chosen, companies may stumble in terms of protection (RAID0), capacity (RAID1), or rebuild time (RAID5). This is why XtremIO X2 arrays include XDP (XtremIO Data Protection) technology. With this you can reap maximum benefits from your SSD capacity while improving data availability.

This is because XDP can fully exploit flash memory random access. Whereas RAID algorithms require data contiguity in order to reposition the read heads, XDP can read and write data anywhere, enabling it to operate far more quickly. Specifically, this peculiarity of flash, associated with a specific parity encoding algorithm, enables far quicker rebuilds in the event of device failure. Since XDP is, moreover, a type N+2 architecture, it even tolerates the simultaneous failure of two SSDs in each module.

These features, along with all those that I do not have time to mention here (thin provisioning, data-at-rest encryption, non-disruptive upgrade, failover/failback, iCDM, etc.) are natively implemented in XtremIO. Protection for your all-flash array is therefore extremely simple. You just need to start by choosing it!

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