| Rather than cover NFS Diskless as an area to manage, I'm going to deviate from the format found throughout this chapter and instead provide a brief description of NFS Diskless. This topic was introduced with HP-UX 10.x. Diskless nodes were implemented with Distributed HP-UX (DUX) in HP-UX 9.x and earlier releases. Distributed HP-UX was first introduced in HP-UX 6.0 in 1986 and was successfully used in many HP installations. The new implementation of diskless nodes as of HP-UX 10.x is NFS Diskless. It has many desirable features, including the following: NFS Diskless is the current de facto standard. It is not a proprietary solution. High-end diskless servers and clients can be symmetric multi-processing systems. Many file system types and features are available, such as UNIX File System, Journaled File System, Logical Volume Manager, disk mirroring, and so on. The System V Release 4 file system layout described throughout this book is implemented. This file system layout is conducive to extensive file sharing, which is used in NFS Diskless. Read-only NFS mounts, such as /usr and /opt/<application> are supported. Distributed HP-UX functionality, such as context-dependent files, has been removed. Servers can be both Series 700 and Series 800 units. The physical link doesn't matter, so servers can use many interfaces such as IEEE 802.3 and FDDI. A server can also assign some diskless systems to one network card, and other systems to other network cards. Diskless systems can boot across a gateway, thereby allowing subnets to be used. Booting is implemented with standard Boot Protocol (BOOTP) and Trivial File Transfer Protocol (TFTP) protocols. Clients can swap to a local disk or swap using NFS to a remote disk.
Many additional features of NFS Diskless exist; however, since our focus is on management, let's take a closer look at this. Using SAM, all tasks related to NFS Diskless administration can be performed. This means that you have a single point of administration for the cluster. You have cluster-wide resources, such as printers and file systems, that can be managed from any node in the cluster. You can defer some operations until a later point in time if a node is unreachable. And, of course, you can add and delete clients in SAM. Using SAM, you get a single point of administration for several NFS Diskless systems. This means that performing an operation in SAM affects all systems in the cluster. The single point of administration areas in SAM include: Printers/Plotters File Systems Users/Groups Home Directories Electronic Mail Backups
Although a great deal could be covered on NFS Diskless and the many improvements in this area over Distributed HP-UX, the key point from an administrative perspective is that SAM provides a central point of administration for NFS Diskless administration. All tasks related to NFS Diskless administration can be performed through SAM. |
