By Henry Baltazar  |  Posted 2004-10-11 Print this article Print

Replicating data over a WAN for data protection and application availability purposes is a difficult process, but for most companies, its necessary for satisfying business and regulatory compliance guidelines. Kashya Inc.s KBX4000 data protection appliance includes new SAN discovery capabilities and granular replication management that can help ease the process.

The new KBX4000 includes Linux support; previous versions worked only with Windows and Solaris. Kashya is working to add AIX and HP-UX support, company officials said. In eWEEK Labs tests, we found that the KBX4000s improvements make it easier to manage and deploy.

The latest edition of the KBX4000, which shipped last month, is also attractive for small and midsize businesses because its less expensive to implement than proprietary synchronous solutions such as EMC Corp.s Symmetrix Remote Data Facility. The price for two KBX4000 appliances (the purchase of two is necessary for WAN replication) is $55,800, which includes snapshot functionality.

The KBX4000 hooks into Fibre Channel storage area networks and replicates data from one site to another over a WAN. The new SAN discovery capabilities make it easier to find SAN resources and quickly use them for data replication in tests. In the previous version of the KBX4000 appliance, we had to manually enter the name of the storage device as well as the target path information. This is a tedious task, especially when trying to set up a remote unit.

The KBX4000s SAN discovery feature cannot resize LUNs (logical unit numbers), but it can control how much of an LUN to use for replication purposes. In the previous version of the KBX4000, we could control bandwidth usage only on an appliance-by-appliance basis.

The updated KBX4000 incorporates group management, which allowed us to prioritize the replication of specific groups of servers. This capability is important because it can be used to ensure that important transaction servers are given all the bandwidth they need in the event of a power outage.

The group management features also allowed us to control the compression levels of replicated data. The KBX4000 uses four compression types, ranging from basic delta block differential compression to advanced application-aware compression (which can be CPU-intensive).

The KBX4000 now uses rapid-snapshot technology, in which snapshots are taken every few seconds, to rapidly replicate data. When a WAN is down for a long period of time, the KBX4000 can throttle back transactions on the application servers. To protect mission-critical databases, IT managers can configure the KBX4000 to pause I/O running on the application servers.

The Kashya driver mirrors all writes from a server so that they go to the primary storage unit as well as the KBX4000.

Like previous versions, the KBX4000 requires that Kashya drivers be installed on all protected servers, which can be an onerous chore. Many other replication tools also have this requirement, however.

To get around the driver problem, Kashya is working with intelligent switch vendors Cisco Systems Inc. and Brocade Communications Systems Inc. to embed the replication functionality in their switches. This will eliminate the need to install the driver on servers. Such switches should be available from Cisco and Brocade early next year.

Senior Analyst Henry Baltazar can be reached at henry_baltazar@ziffdavis.com.

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