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Panasas boosts scale-out NAS offerings with flash and disk AS18

Scale-out NAS specialist Panasas has replaced its AS16 appliance with two AS18s that combine flash tier and helium-filled hard drives in 4U units that scale up to 20PB

Scale-out network-attached storage (NAS) array maker Panasas has revamped its core range of clustered NAS hardware with the addition of helium-filled hard disk drives (HDDs) and a flash storage tier.

The ActiveStor 18 (AS18) appliances come with standard 4TB HDDs or 8TB HGST He8 helium-filled hard drives for a claimed 33% increase in storage density.

A 4TB drive configured base unit comes with 66TB of capacity, including 140GB of flash in 4U. The base unit with 8TB helium drives has capacity of 132TB and 280GB of flash in 4U. Those units can be scaled up to a published maximum of 20PB, although Panasas says the ceiling can be far higher if required.

Scale-out or clustered NAS is the successor to traditional NAS file access storage. Its key benefit is the ability to handle very large numbers of files on a single namespace under which hardware can be added to scale capacity or increase performance without disruption.

Scale-out NAS products are aimed at sectors with high volumes of unstructured files such as movie processing, as well as big data use cases such as life sciences and oil and gas.

Panasas scale-out NAS products run the company's proprietary parallel file system, PanFS, which scales to billions of files and can handle theoretically unlimited file sizes.

Access protocols are Panasas proprietary DirectFlow plus network file system (NFS) and server message block (SMB).

Customers can include up to nearly 3% of capacity in AS18 appliances as flash storage. This, however, is not intended as the first tier of storage. That task is handled in Panasas by RAM used as tier one, which is doubled in size to 160GB from the predecessor AS16 hardware.

In the Panasas scheme, said product management vice-president Geoffery Noer, working data is held in RAM with flash only used for metadata and small files, while large files are striped to disk.

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“We've found that 60% to 80% of files customers store are small files such as metadata files, but they only form 1% of capacity in big data workloads so it makes no sense for them to be held in cache,” he said.

The AS18's 8TB helium-filled drives, meanwhile, offer increased capacity and lower power usage. That's because helium is about 1/7th the density of air and this reduces friction for spinning components in the HDD, when they start up and as they run.

Array data protection is provided by Panasas Raid 6+, which provides triple parity compared with the double parity of standard Raid 6. Also, the software-based protection can discover disk errors at sector level before a drive fails and rebuild failing sectors to reserved drives. AS18 appliances will ship from September 2015.

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