Subdisk : A subdisk is a set of contiguous disk blocks that represent a specific portion of a VxVM physical disk. (LVM comparison = Physical Volume although LVM doesn't allow us to assign a logical name to a disk.) Using a logical name, e.g., FinanceDisk01, means that regardless of the device file name, the Disk Media name remains the same.

This should be avoided, because even if the device file changes (you rewire a SAN/SCSI interface), the Disk Media Name will remain the same. By default, the name used is the same as the associated device file. VxVM will associate a logical name (Disk Media Name) with each physical disk. (LVM comparison = Volume Group.)ĭisk Media : This is the name given to an individual physical disk. The first disk group created on a system must be called rootdg even if it does not contain root/boot volumes. From this pool of disk space, we can create individual volumes that can be constructed using various layout policies, e.g., mirrored, striped, RAID 5, and so on. If one host crashes, the other host can take over the failed host's disk drives, as well as its disk groups. Disk drives can be shared by two or more hosts, but can be accessed by only one host at a time. Disk groups enable high availability because a disk group and its components can be moved as a unit from one host machine to another. Disk groups enable you to group disks into logical collections. You can create additional disk groups as necessary. For example, data for accounting applications can be organized in a disk group called acctdg. You group disks into disk groups for management purposes, such as to hold the data for a specific application or set of applications. If you are new to VxVM, it will give you some idea of the forthcoming concepts.ĭisk Group : This is a collection of physical disk drives that are associated with each other. Let's walk through Table 7-1 and discuss each VxVM term in turn. Coming from an LVM-led background, I find Table 7-1 useful in that I can start to acclimatize myself with some of the new jargon. If you are an HP-UX administrator familiar with LVM coming to VxVM for the first time, then Table 7-1 may be of some use. If you are new to LVM and VxVM, Table 7-1 will be of little importance to you or make much sense. Here is a quick comparison between the key terms and technologies used by both LVM and VxVM (Table 7-1): Table 7-1. If you fit into this category, it is natural to want to compare the technologies of LVM with the technologies of VxVM. Many existing HP-UX administrators will be coming to VxVM from a background of understanding and having worked with HP's LVM. This is the version we use in our examples. The current version of VxVM on HP-UX is version 3.5.

Veritas volume manager 3.5