Metadata Contents; Sample Metadata - Red Hat LVM ADMINISTRATOR FOR RHEL 4.5 Administrator's Manual

Appendix D. LVM Volume Group Metadata

2. Metadata Contents

The volume group metadata contains:
• Information about how and when it was created
• Information about the volume group:
The volume group information contains:
• Name and unique id
• A version number which is incremented whenever the metadata gets updated
• Any properties: Read/Write? Resizeable?
• Any administrative limit on the number of physical volumes and logical volumes it may contain
• The extent size (in units of sectors which are defined as 512 bytes)
• An unordered list of physical volumes making up the volume group, each with:
• Its UUID, used to determine the block device containing it
• Any properties, such as whether the physical volume is allocatable
• The offset to the start of the first extent within the physical volume (in sectors)
• The number of extents
• An unordered list of logical volumes. each consisting of
• An ordered list of logical volume segments. For each segment the metadata includes a
mapping applied to an ordered list of physical volume segments or logical volume
segments

3. Sample Metadata

The following shows an example of LVM volume group metadata for a volume group called
.
myvg
# Generated by LVM2: Tue Jan 30 16:28:15 2007
contents = "Text Format Volume Group"
version = 1
description = "Created *before* executing 'lvextend -L+5G /dev/myvg/mylv
/dev/sdc'"
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