Novell High Availability Server™ (NHAS)
NHAS allows you to use Intel architecture equipment as part of two servers and a shared disk array connected to them. By pairing two independent servers in an Active / Active configuration, NHAS allows each NetWare server to mount the data of the other server if one of the servers in the cluster fails. Monitoring of servers is carried out through a conventional network connection, a disk channel, and / or a dedicated connection, using additional network cards. When one of the servers does not respond to requests, the recovery process (failover) begins. Client and server applications that were running on a failed server can be configured to automatically restart on the surviving server.
NHAS provides support for volumes, virtual IP and IP addresses of major business applications such as Oracle®, web servers and others, automatically moving them from the failed server to the surviving one. NHAS also dynamically redistributes user licenses by automatically adding user licenses and rights to the surviving server from the failed server. When a failed server is restored, then user licenses and rights will be returned to it.
NHAS will also help you avoid planned network outages by stopping a running server for upgrades or maintenance, while the remaining server will provide users with unhindered access to network resources. Application performance, when using NHAS, will be higher, since the workload is distributed between the two servers.
NHAS supports the centralization of rapidly growing data resources, their guaranteed delivery and storage on low-cost mass storage devices. This is because NHAS uses standard RAID devices, which can be easily expanded in capacity. Plus, you can use the second server as a working platform to get all the benefits from your investment.
two servers working with licensed copies of NetWare 4.11;
each server must have at least one local disk for the SYS volume;
at least one shared disk subsystem connected to both servers.
For example, the Compaq Proliant Fiber Channel disk subsystem with one host adapter in each server or the IBM 3518 Shared SCSI disk subsystem.
It is possible to use other disk subsystems:
Novell certified network cards are used to connect servers to a working network;
dedicated connection between servers (optional).