IBM Expands Flash Drives For Power8 Iron
November 27, 2017 Timothy Prickett Morgan
Back in October, IBM announced a new lineup of small form factor disk drives with 1.8-inch and 2.5-inch form factors as well as updates for 2.5-inch flash drives that were a little bit on the beefy size. We suspect that these drives were intended to be co-launched with Power9-based servers, as well as some new, skinnier flash drives that were announced just before the Thanksgiving holiday in the United States.
On November 21, in announcement letter 117-108, Big Blue rolled out the new 2.5-inch flash drives that are based on 3D NAND flash memory and are rated at a pretty high ten drive writes per day for their duty cycle over a five year period, which is very reasonable for the warranted life of any storage device. The new flash drives support 4224 and 528 byte sector formats, but do not support 512 byte formats.
These 2.5-inch flash SSDs are available in 387 GB, 775 GB, and 1.5 TB capacities and they are outfitted with SAS ports and attached to any Power8 machine, regardless of operating system restriction, so long as they have SAS controllers to attaching to media. They can also be used in EXP24S and EXP24SX storage expansion drawers with SAS RAID controllers for extending the capacity in rack servers. As usual, IBM has distinct feature codes for the Power8 machines that can run IBM i, AIX, or Linux atop the PowerVM server virtualization hypervisor versus those that can be attached to Linux-only machines that run in bare metal mode or have Linux nestled in partitions atop the PowerKVM hypervisor. Here is the grid describing the feature codes:
There are some gotchas with these new flash SSDs. Customers using the four-core Power S814 – one of the more popular boxes to run IBM i – cannot use a flash drive with more than 387 GB of capacity. Which is utter nonsense. IBM doesn’t allow customers to mix 4 KB and 512 byte drives to be mixed in the same arrays, and you also can’t mix drives of different capacities in the same arrays, which makes sense for balanced performance and symmetry reasons. You can’t mix flash SSDs and disk drives in an array for the same reason, unless customers are using IBM’s Easy Tier array software to do hierarchical storage management software on it. One last thing: The 1.5 TB flash drive is only available in 4 KB formats.
IBM is charging a premium for the drives formatted in 528 byte formats, which is used for PowerVM and IBM i. The 387 GB drive for 528 byte formats costs $2,375, or $6.14 per GB. It costs $200 less for the fatter formatting, which works out to $5.62 per GB. The 775 GB flash SSD costs $3,375 or $4.35 per GB with the 528 byte format, and $3,175 or $4.10 per GB for the 4 KB format. The 1.5 TB drive is only available in the 4 KB format and it costs $5,975 or $3.85 per GB. Obviously, these flash drives cost a lot less per unit of capacity as they get fatter.
The new flash SSDs will be available on December 1, and were also undoubtedly aimed at Power9 servers, too.