Zadara Storage Virtual Private Storage Array review

Enterprises moving their data centres into the cloud are facing some difficult decisions as many service providers have numerous limitations when it comes to delivering multi-terabyte storage. Zadara’s VPSAs (virtual private storage arrays) solve these key issues as they deliver everything you could want from on-premises storage arrays, puts it in the cloud and uses a simple pay-per hour billing scheme with no minimum contract.

Zadara works with all the biggest cloud providers and delivers a software defined storage service that overcomes the problems associated with cloud-based IP SAN and NAS file storage. Amazon Web Services (AWS), for example, doesn’t support IP SANs or SMB shared storage and has only recently started trialing an NFS solution.

Its EBS (elastic block storage) is limited to 16TB volumes which can only be mapped to a single virtual machine and while AWS supports encryption, it owns the key management system. Microsoft’s Azure doesn’t offer IP SAN block storage, supports SMB but not NFS, has no encryption features and provides up to 1TB block-based and 5TB file-based volumes.

Zadara offers much more as along with IP SANs plus SMB and NFS shared storage, its VPSAs support 100TB volume sizes. Snapshots and replication are standard features while for data encryption, only users has access to the keys.

Let’s get physical

Zadara’s storage arrays are located in around 38 global data centres including AWS, Azure, TelecityGroup, Dimension Data and FlexiScale. They are either co-located in the same centre or in some cases, in an adjacent building.

Physical arrays comprise standard 4U Intel storage servers connected over 10GbE or 40GbE Ethernet links. For AWS, they’re directly linked using multiple 10GbE connections while Azure uses Microsoft’s ExpressRoute with multiple connections ranging from 100MB to 10GbE.

The VPSAs comprise virtual controllers each with their own CPUs, RAM and storage on a dedicated network. Physical drives are mapped across all VPSA nodes in the storage grid so there’s no single point of failure.

Each customer is completely isolated so avoiding any performance issues which can afflict other shared cloud storage solutions. Furthermore, customers can dynamically scale CPU, RAM and drive allocations to keep in step with changing workloads.

Baby or Blazing+?

For testing, we used AWS and set up multiple EC2 virtual server instances each running Windows Server 2012 R2. To create VPSAs, we logged into Zadara’s management portal, selected AWS from the list of cloud providers and chose our engines.

Zadara offers six engine sizes where Baby gives you two virtual CPUs, 4GB of RAM and up to 5 drives. At the top end is the Blazing+ engine which provisions 16 CPUs, 32GB of RAM and up to 80 drives.

Drive choices are 600GB SAS, 5TB SATA and 200GB SSDs and any drive mix can be assigned to a VPSA. Another bonus is mirrored SSD caches are automatically added to the engine and after creation, we could adjust their sizes.

VPSA configuration

The Zadara portal provides URL links to each VPSA which are accessible from within the cloud provider’s account. All we had to do was RDP to an EC2 instance and paste the relevant URL into a browser.

Our first job was to assign the VPSA controllers to the servers where each uses dual-redundant links. For our assigned drives we could create RAID1, 5 or 6 arrays and place these in storage pools.

Multiple arrays can be placed in the same pool so it’s possible to create RAID10, 50 and 60 arrays. During this phase we also enabled the SSD cache which we could turn on or off later on as required.

We created thinly provisioned IP SAN and NAS volumes and for the latter, we could enable SMB or NFS access (or both). The EC2 servers must be registered with the VPSA and Zadara’s script neatly automated this process.

Snapshots, clones and replication

Mapping NAS shares to our EC2 servers was a doddle as the SMB export path was shown in the volume properties. For access security, we could assign shares to Zadara users and groups and integrate with Active Directory.

Share performance is right on the money. Running Iometer on two EC2 instances with separate volumes on the same SAS RAID array saw both return sequential read and write speeds of 113-114MB/sec. We also saw good I/O rates as using 4K Iometer block sizes returned around 16,000 IOPS on each server.

Snapshots can be scheduled at regular intervals and cloned and mounted as new volumes. This pays dividends for rapid recovery as we used simple drag and drop maneuvers to restore selected files from a snapshot clone.

There’s more as VPSAs can be asynchronously replicated to others and the targets can be with other service providers. Zadara’s online migration also allows volumes to be moved to other storage pools, possibly where a higher performance is required.

Conclusion

We found Zadara’s VPSAs remarkably easy to deploy and manage as its RAID arrays and volumes are really no different to those you’d find on a local storage network. It provides everything you can’t get from most other cloud storage providers while its pay-per-hour billing system makes it very affordable.

Verdict

Zadara provides the cloud storage capabilities enterprises are crying out for. Its VPSAs deliver standard IP SAN and NAS services, are easy to create and manage and its maximum cloud volume sizes are comparatively enormous