HP Visualize J5000 hp Visualize J5000, J7000 workstations owner's guide (a4978 - Page 80

Hot-Pluggable Hard Disk Drives The Hot-Plug Process The Hot-Plug Process The physical aspect of inserting and removing a disk drive, as discussed in the previous section, is straightforward. However, the operating system must be prepared for the insertion or removal of a disk, or unexpected and harmful effects may occur. There is a significant difference between the terms "hot-pluggable" and "hot-swappable." Hot swapping happens at the device level; that is, a hot-swappable device manages insertion/removal on its own without assistance from HP-UX commands. The disk drives in the J5000 and J7000 are not hot-swappable; they are merely hot-pluggable. Thus, a manual software procedure must be done in order to safely remove or insert disk drives while the system is running. The reason the hot-plug process exists is that you might need to replace a defective disk drive in a high-availability system while it is running. Replacing a Failed Disk Drive In the context of replacing a failed disk drive, the system administrator must determine which disk has failed. Depending on how the system was set up, the identity of the failed drive may or may not be obvious. This determination may be done in either of two ways: • Tracking the error messages written by the LVM (Logical Volume Manager) to the system console and/or a log file. For information on LVM commands, see the man pages for vgdisplay, vgchange, lvreduce, vgcfgrestore, lvlnboot, lvextend, etc. • If installed, run the diagnostic utility Support Tool Manager (xstm) to determine disk malfunction. The removal of a defective disk drive from an active file system is supported through LVM commands if hot-pluggable disks have been configured into the HP-UX file system with LVM. To provide high availability, without impact to users, the disks must also be configured as mirrored disks. Disk-mirroring is accomplished through use of the MirrorDisk/UX software (HP part number B2491A); for information on classes, see http://www.hp.com/education/courses/h6285s.html. No graphical user interface is currently offered through the System Administration Manager (SAM) for doing the required LVM commands, 80 Chapter 3