HP StorageWorks Modular Smart Array 1500 CS review
HP’s latest StorageWorks family aims to offer a cost-effective entry point for SMEs into the world of Fibre Channel (FC) SANs. You can start off with a complete two-node setup as reviewed here, but HP also offers a basic SAN Starter Kit, which includes a 1500 cs shelf with one controller, a SCSI or SATA drive enclosure, plus an eight-port FC switch, four HBAs and fibre-optic cabling – prices for this start at £8,909.
The StorageWorks product allows both SCSI and SATA enclosures to be connected to the same controller, so there’s plenty of room to expand. However, if you’re after raw capacity over performance, SATA is the better bet. Up to eight SATA enclosures can be linked to one controller, whereas only four SCSI enclosures are supported. Unlike NetApp’s FAS3020c, which uses fibre-optic links, HP’s disk enclosures are DAS (direct-attached storage) devices and connect over standard SCSI cabling.
The 1500 cs offers plenty of fault-tolerant features. Along with multiple hot-swap power supplies and fans, it has a pair of hot-swap bays at the front that accept HP’s MSA1000 modules. Access is as easy as removing a hard disk. The modules slide out from the front, and releasing two clips allows the lid to be raised for easy access to the cache memory sockets. These modules are common to all HP’s Smart Array StorageWorks products, so you can upgrade from older HP storage products simply by swapping the modules into the newer chassis.
The MSA1000 modules use a clear LED panel, which provides plenty of information about the unit’s status. They’re also endowed with a reasonable hardware specification, although the pair of embedded Ultra160 SCSI controller chips give an indication of the design’s age. However, each module came supplied with the full complement of 512MB of battery-backed-up cache memory. With a pair of modules installed, only one will be active, while the other acts as a standby, and data in the active cache is automatically mirrored to the standby cache.
Installation is fairly straightforward, as you simply daisy-chain the disk enclosures to the controller using standard SCSI cables. Each SCSI I/O module has a pair of connectors, with one supporting SATA only and the other accepting SCSI enclosures as well, and the 1500 controller has room for up to four SCSI I/O modules. SAN connectivity is limited, as each controller has one 2Gb/sec FC I/O module assigned to it, but only the active one can be used and it’s not possible to add any more modules. Consequently, all your servers will be accessing the 1500 cs over a single 2Gb/sec FC link.
The storage array can be managed with a direct serial connection and we were impressed by how easy the CLI was to use. HP’s Java-based ACU (array configuration utility) also offers easy access to the controller and disk arrays and can be accessed either by booting the server with the product CD-ROM, running it locally or remotely from Windows on an attached server, or integrating it into HP’s System Insight Manager software suite. One highly annoying limitation of this setup is that HP has restricted management access to a small number of supported FC HBAs, which, naturally, are its own brand. With a standard QLogic 2310F card, we could access the disk arrays, but the ACU refused to work unless we used a StorageWorks-branded HBA.
Disks can be carved up into a variety of configurations, which are presented to the SAN as LUNs (logical unit numbers). Along with the usual RAID suspects, HP offers the proprietary ADG (advance data guarding) feature that’s similar to RAID5 but uses two sets of parity data. Each set will eat up the capacity of one physical drive member, but it does allow the array to function even if two drives fail. Either way, you simply pick the member disks, choose the array type, select hot-standby drives and leave the controller to build it. Arrays can be expanded on-the-fly, so it’s easy to add new drives and enclosures to existing configurations. HP’s SSP (selective storage presentation) also provides access controls, as you can view all logged-in HBAs and decide which can access each logical drive.