Configuring Disk Devices
Volume Group Device Files Volume groups are referenced via device files, too. Each volume group has a subdirectory under /dev containing a group device file for the volume group itself, as well as the device files for all of the logical volumes within the volume group. The name of the volume group’s subdirectory determines the volume group’s name. Examples /dev/vg01 /dev/vg01/group
# directory containing device files associated with vg01 # device file for vg01 volume group
Logical Volume Device Files Logical volume device files are stored in the directory of the volume group to which they belong. Each logical volume has two device files: one is used when accessing the logical volume in character mode, the other is used when accessing the logical volume in block mode. Examples /dev/vg01/lvol1 /dev/vg01/rlvol1
# block device file for logical volume "lvol1" in vg01 # raw device file for logical volume "lvol1" in vg01
LVM Major and Minor Numbers Like all other device files, every logical volume and volume group device file must have both a major and a minor number. All LVM device files have major number 64, the major number associated with the LVM kernel driver. The first two digits of the minor number identify which volume group the device file is associated with. The last two digits identify the logical volume associated with the device file. Name: /dev/vg01/lvol2 Major #: 64 Minor #: 0x010002 Example
• The major number for this device file, like all LVM device files, is 64. • The first two digits in the minor number (01) indicate that this is in vg01. • The last two digits in the minor number indicate that this is lvol2. Questions If vg02 has three logical volumes created using the default naming convention 1. What directory would contain the logical volumes’ device files?
8-9
H3064S A.01 © 1999 Hewlett-Packard Company