HP-UX HB v13.00 Ch-13 - LVM

HP-UX Handbook – Rev 13.00 Page 107 (of 110)
Chapter 13 LVM
October 29, 2013
 If you have a good prior backup, restore its contents. Since the new file
system in the smaller logical volume will be smaller than the original file
system, you may not have enough space to restore all your original files.
 Use the new file system for creating and storing a new set of files (not for
trying to restore the original files).
 If you do not have a good prior backup, attempt to restore as many files as
possible from any backup. Again, there is no guarantee that complete data
will be recoverable from this backup.
No Response or Program Output from an Inaccessible Disk
You might occasionally see long periods of apparent inactivity by programs that are
accessing disks. Such programs may be "hung", waiting for access to a currently
inaccessible disk. Messages indicating the disk is offline will also appear on your
system console.
If the logical volume is mirrored onto another disk, the hang will only last until the disk
driver returns (about a minute or perhaps a little longer). LVM then marks the disk as
offline and continues the operation on any remaining mirror disk. LVM will only write to
or access the mirror copy until the offline disk is returned to service.
If the logical volume is not mirrored, or if the mirror copies of the logical volume are also
not available, the program will remain hung until a disk becomes accessible. Therefore,
if your program hangs, you should check for problems with your disk drives and, if
necessary, restore them to service as soon as possible.
Commands Overview
command
desciption
vgcreate
create a new VG
vgdisplay
display information about the VG
vgchange
activate/deactive a VG or change parameter of a VG
vgextend
add a new PV to the VG
vgreduce
remove a PV from the VG
vgremove
remove a VG (better use vgexport)
vgcfgbackup
backup the LVM header of a disk to a file
vgcfgrestore
restore the LVM header from a file to a disk
vgexport
remove the info of a VG from the system
vgimport
create a previously exported VG on this system
vgscan
recontruct /etc/lvmtab from the LVM headers on disk