IT Pro Verdict
IBM’s System Storage DS3500 arrays are a good choice for SMBs as they can start small and scale easily with demand. Few other SAS storage array vendors can match IBM’s starting price or its support for DAS applications plus optional FC SAN or IP SAN upgrades making it very flexible.We found performance over the lab’s 8Gbps FC SAN to be excellent and the high expansion potential is made all the more impressive as the only limiting factor is the number of disk drives rather than disk shelves.
SMBs looking for low cost network storage arrays often have to make compromises as SATA hard disks have traditionally been their only option. IBM's new System Storage DS3500 family are arrays built around high-speed 6Gbps SAS disks but have a surprisingly low starting price.
You have a choice of two head units with the DS3512 reviewed here supporting a dozen 3.5in hard disks. The DS3524 is also a 2U appliance but this can handle up to twenty-four 2.5in drives and has a starting price of 3,087. Both models have a single hot-swap controller module which can be upgraded with a second where they run in active/active mode.
The DS3512 can be fitted with a wide variety of disks. Along with standard SAS and full disk encryption (FDE) SAS disks. you can fit near-line SAS disks which have a spindle speed of 7,200rpm instead of the faster 10,000 and 15,000 rpm speeds of more traditional SAS disks. They have the high capacity and low cost of SATA disks but with SAS drive electronics.
Generally sold in 2TB capacities, near-line SAS drives are sounding SATA's death knell for business storage applications. They do away with the need for a SATA to SAS interposer thereby reducing manufacturing costs plus potential points of failures and they have the same level of host queuing support as standard SAS drives.
The controllers have an extensive range of data port options. You start with a pair of fixed 6Gbps SAS ports for DAS connections but there's room for an optional host card. IBM has dual-port 6Gbps SAS or four-port 8Gbps FC and Gigabit iSCSI options. The DS3512 on review came with the FC host card.
