Part III: And more storage arrays

Continuing my research on all the storage array vendors out there.....

3ParData
Not a new vendor but I haven't looked at them in a while. 3Par makes a fairly traditional block storage rack with 3U and 4U disk trays, a 4U dual controller modular, dual power supplies, etc. Available with FC and iSCSI SAN interfaces. They provide the usual set of RAID levels and data services including snapshot and remote copy and a 'single pain' management GUI that includes tools for monitoring and managing storage resources, access patterns, and for migrating data between RAID levels.

One feature they have developed is the ability to Underprovision. You can create several volumes that can present LUNs that are larger than the amount of available disk space. You have to leave some amount of disk space in a free pool. Then, as one or more of the underprovisioned LUNs fill up, the controller will automatically take space from the free pool as necessary. Another nice (although I'm not sure new) feature is the ability to migrate data between RAID levels online as access patterns and the desired SLA change.

In summary, nothing bleeding-edge here. They've been around a while so I would hope they have most of the bugs worked out so for someone just needing reliable block storage with some scaleability, ability for snapshot/backup and remote mirror, this might be a good choice.

Digi-Data
Not new either. Another fairly standard RAID array in the middle of the pack. Features include FC or iSCSI host interface (4 ports/controller), FC or SATA disks, snapshot, sync and async remote copy, standard RAID levels and also claim to have RAID 6. Available in a 3U, 15-drive dual-controller model. Also sell a 1U RAID head that uses stand-alone JBODs on the back-end.

Xyratex
More mid-range RAID. 2U and 3U RAID trays. FC host, SAS and SATA disks. Snapshot, remote copy, etc.

Compellent
Block storage provider who's value prop is a set of block data services. Claim to provide the 'Only SAN with Automated Tiered Storage'. I'm not sure I believe that but their RAID subsystem will track properties of data and automatically migrate to different tiers of storage. This would have to be at the block level so they must be doing this at the granularity of some number of blocks.

They also have an underprovisioning (called Thin-Provisioning) feature to let users create LUNs that are larger than the available storage and pull from a free pool as necessary. Also, claim to have CDP. They call it Continuous Snapshots.

Celeros
Going for low cost. Do a low-end array with ethernet interface running both iSCSI target and NAS. My guess is they use Linux internally on a commodity motherboard and OEM a low-end RAID controller. Targeting small business.

Stonefly
Really going for the low-cost leader in an iSCSI storage array. Have a product called a 'Storage Concentrator' that serves as iSCSI Target. Looks suspiciously like a 1U Dell rack server with the Dell logo replaced with one that says Stonefly. My guess is it runs Linux with an iSCSI target driver such as Wasabi. Also available in a 3U array with a single integrated iSCSI controller. Has battery-backed cache but no controller failover.