Compellent adds file-level access to SAN
Unified storage here we come
Compellent is adding integrated file-level access to its SAN product, and using Sun's open source ZFS to do so.
The zNAS product is a 1U enclosure running the file access software on diskless, dual quad-core Nehalem hardware, which can be clustered in two nodes for high availability. It has 1Gbit Ethernet client access, with 10GbitE coming, and 8Gbit/sec Fibre Channel access to the backend storage. There are 24GB and 48GB memory options.
The file access is conceptually layered onto Compellent's storage array such that it benefits from all the features of that product concerning a single virtual pool of storage, thin provisioning, solid state drives, multiple types of hard drive, automatic data progression for moving data blocks between tiers and so on.
The Compellent SAN thus becomes a network-attached storage (NAS) product, offering NFS and CIFS access, with a single management facility for both the file world and the block, storage area network (SAN) world.
This is, in effect, a significant update of the existing NAS head facility which is a 1U Xeon-powered box running Microsoft's Windows Storage Server. The box has been given an extra slug of processing power and WSS replaced with ZFS.
ZFS or the Zettabyte File System is a 128-bit file system which is outrageously scalable and has checksum technology to verify data integrity. Compellent has chosen Nexenta to be its ZFS development partner, because of its "deep engineering-level expertise". It says the product is backed all the way and supported by Compellent.
Compellent says it asked its customers what they wanted and a big priority was integrated, high-performance and scalable file access. Marketeer Bruce Kornfeld said: "ZFS fit the bill perfectly."
He was confident that the lawsuits over NFS between NetApp and Sun, now Oracle, were very low-risk, saying that in ten years of open source software lawsuits had raised their heads but nothing had happened. Also: "Oracle is very committed to its open storage acquisition."
It cites IDC as saying that the file market is growing ten times faster than the block storage market, although it also quotes Gartner saying the SAN market is currently five times bigger than the NAS market.
Kornfeld said: "Creating a new fileshare is very easy. Most everything is done automatically on the backend." Compellent says its customers should find that "unified SAN/NAS management simplifies provisioning and recovery of virtual servers in VMware, Microsoft, Citrix and Oracle environments".
Unified block and file storage has become very fashionable of late, with NetApp having helped make it mainstream, Pillar offering it since day one, and EMC looking to converge its CLARiiON block and Celerra file storage products. Many iSCSI arrays, from vendors such as Reldata and Nimbus, have NAS access facilities such that it's rare to find an iSCSI array these days that doesn't have file access.
Pillar CEO Mike Workman distinguishes between Pillar and NetApp's native unified storage and NAS head or gateway-based approaches, blogging that: "Most vendors stick a NAS gateway device in front of their block device. Interposing a gateway gives you two management interfaces and the management overhead of provisioning storage on both devices to get the job done once."
Compellent says it has a single pane of glass management and the provisioning is not difficult because most of it is automated and done by the backend SAN storage.
Customers can buy Compellent's unified storage with a two-node clustered zNAS setup or buy the clustered zNAS nodes only. The products will be generally available by the end of June.
Excluding taxes, maintenance and services, Compellent unified storage starts at £54,600 with two clustered zNAS nodes, two clustered SAN controllers, 8.7TB of SAS storage capacity and Compellent SAN software. Adding two clustered zNAS nodes to an existing Compellent SAN starts at £23,400 excluding taxes, maintenance and services. ®