Information Collection |
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You can collect information about your LVM configuration
using the vgdisplay, lvdisplay, pvdisplay, and lvlnboot commands.
As noted in “Planning for Recovery”, periodically collect the outputs from the commands listed in Table 4-1.
Table 4-1 LVM Information to Collect and Maintain
| Command | Scope | Purpose |
|---|
ioscan -f | | Prints I/O configuration |
lvlnboot -v | | Prints information on root, boot,
swap, and dump logical volumes. |
vgcfgrestore -l | All volume groups | Prints volume
group configuration from the backup file. |
vgdisplay -v | All volume groups | Prints volume
group information, including status of logical volumes and physical
volumes. |
lvdisplay -v | All logical volumes | Prints logical
volume information, including mapping and status of logical extents. |
pvdisplay -v | All physical volumes | Prints physical
volume information, including status of physical extents. |
In addition, use the lvmadm command for two purposes:
To determine which volume group versions are supported
by your release of HP-UX 11i Version 3. For example, if your release
supports Version 2.1 volume groups, lvmadm displays
the following:
# lvmadm -t -V 2.1
--- LVM Limits ---
VG Version 2.1
Max VG Size (Tbytes) 2048
Max LV Size (Tbytes) 256
Max PV Size (Tbytes) 16
Max VGs 2048
Max LVs 2047
Max PVs 2048
Max Mirrors 5
Max Stripes 511
Max Stripe Size (Kbytes) 262144
Max LXs per LV 33554432
Max PXs per PV 16777216
Max Extent Size (Mbytes) 256 |
If your
release does not support Version
2.1 volume groups, it displays the following:
# lvmadm -t -V 2.1
Error: 2.1 is an invalid volume group version. |
To display the contents of the /etc/lvmtab and /etc/lvmtab_p files in a human-readable
fashion. For example, the following command displays the contents
of the LVM configuration files for all Version 1.0 volume groups on
your system:
# lvmadm -l -V 1.0
--- Version 1.0 volume groups ---
VG Name /dev/vg00
PV Name /dev/disk/disk34_p2 |
In addition, there
are some tools available from your HP support representative:
dump_lvmtab: prints the contents
of the /etc/lvmtab file in human-readable fashion.
vgcfgdisplay: prints the contents
of an LVM volume group configuration backup file (as created by vgcfgbackup), such as the volume group information, the
logical volume information, physical volume information and logical
extent distribution.
Maintenance Mode Boot |
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LVM maintenance mode boot is a special way to boot your system that bypasses the normal LVM
structures. Use it only for problems that prevent the system from
otherwise booting. It is similar to single-user state in that many
of the processes that normally start do not start, and many of the
system checks are not performed. LVM maintenance mode is intended
to enable you to boot your system long enough to repair damage to
the system LVM data structures typically using vgcfgrestore, which then enables you to boot your system normally.
Normally, the boot loader uses the LABEL file in the LIF volume to determine the location of the boot file
system and the kernel /stand/vmunix. The LABEL file also contains the starting block and size of
the root file system.
Under a maintenance mode boot, the boot loader
attempts to find the boot file system at the start of the boot disk's
user data area rather than using information from the LIF volume.
To obtain the root file system's starting block and size, the
boot loader reads the file /stand/rootconf. Since LVM is not enabled,
the root file system must be allocated contiguously.
A maintenance mode boot differs from a standard
boot as follows:
The system is booted in
single-user mode.
No volume groups are activated.
Primary swap and dump
are not available.
Only the root file system
and boot file system are available.
If the root file system
is mirrored, only one copy is used. Changes to the root file system
are not propagated to the mirror copies, but those mirror copies are
marked stale and will be synchronized when the system boots normally.
To boot in maintenance mode on a system with a
root disk configured with LVM, use the -lm option
to the boot loader. On an HP 9000 server, enter the following command:
On an HP Integrity server, enter the following
command:
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| |
|
 | CAUTION: When you boot your system in maintenance mode,
do not activate the root volume group and do not change to multiuser
mode (for example, by specifying /sbin/init 2).
Doing so can corrupt the root file system. |
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| |
|
When you have repaired or restored the LVM configuration
information, reboot the system using the following command:
For more information about LVM maintenance mode
boots and troubleshooting problems with LVM structures, see Disk and File Management Tasks on HP-UX, published by
Prentice Hall PTR, 1997.
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