The IETF only ratified iSCSI last week – or more accurately, raised its status to that of proposed standard – and backers of the IP storage protocol are hoping that the market will at last be spurred into supporting it. NetApp’s director of technology Keith Brown said that although other vendors have been shipping iSCSI for some while, NetApp did not want to jump the gun.

iSCSI allows low-cost, familiar Ethernet or other IP-supporting networking hardware to create block-level storage networks, and so offers a lower performance but cheaper alternative to the expensive and exotic Fibre Channel. NetApp expects that iSCSI will finally take-off this year.

What you’re seeing is the begininng of a huge market. iSCSI fundamentally changes the eoconomics of block-based SAN hardware, Brown said. iSCSI is mostly commonly pitched as technology for smaller customers who have not yet built a SAN, although it may also be used by large corporations to build low-cost branch lines out from their core Fibre Channel networks. NetApp is a mid-range to high-end supplier, and its cheapest 800 series filers start at $15,000 list.

Until last year, NetApp’s hardware was focussed entirely on file-level storage. In October 2002 it underwent something close to an epiphany and launched an update to its OnTap operating system that added support for Fibre Channel-based block-level data transfers to the previous file-level support. This week’s announcement adds iSCSI-based block-level support, as a free-of-charge software update.

Since the launch of its NearStore storage arrays in April last year, NetApp has sold 4PBytes of capacity of the low-cost machines, proving that the idea behind the box holds water. The NearStore uses PC-style ATA disks instead of the more expensive SCSI or Fibre Channel disk usually used in data center arrays, and is intended to create a new storage tier.

The R150 launched this week has not yet officially replaced last yea’s NearStore R100, but Brown did describe it as a new generation, and the R100’s prospects are now heavily deflated. By replacing the R100’s 160GB ATA drives with 250GB drives, and being able to handle more disks, the R150 has doubled its capacity to 24TB, but maintained a price of around one cent per MB. Bigger cache, and improved controllers and I/O subsystem have given the R150 a throughput of 430 GB/hr.

The software associated with the NearStore has also been upgraded. The number of incremental snapshots that can be stored on one volume has been raised from 31 to 255. Black claimed that this new snapshot capacity is much greater than that offered by any other supplier.

One of the major uses of the NearStor is as a back-up device, in some cases replacing tape and in others acting only as a high-speed staging post to ease the backup process. In either case this may involve the use of NetApp’s SnapVault software, which like other snapshotting products makes a record of the incremental changes to data rather than an entire copy of the data. SnapVault does this at the block-level rather than the file level, something which NetApp said is unique, and allows snapshots to occupy less physical space and take less time transfer from machine to machine.

This week the company announced that SnapVault can now copy data from third-party arrays to to the NearStore, and no longer just from NetApp filers. EMC, HP, Hitachi, and other arrays are now supported. To gain this third-party support , customers will have to install agent software on their host servers. NetApp described this overhead as being no worse than for any other backup product.

Unsurprisingly, a long list of third-party suppliers of backup management software suppliers have promised to integrate the new third-party array capabilities of SnapVault with their products. Only BakBone has already completed the integration however.

Source: Computerwire