|
|
|
|
|
To convert LVM volume groups to VxVM disk groups
vgdisplay to identify the candidate LVM volume groups and the disks that comprise them. You can also use the listvg operation in vxvmconvert to examine groups and their member disks, and the list operation to display the disks known to the system as shown here:
Volume Manager Support Operations
Menu:: VolumeManager/LVM_Conversion
1 Analyze LVM Volume Groups for Conversion
2 Convert LVM Volume Groups to VxVM
listvg List LVM Volume Group information
?? Display help about the menuing system
The list operation displays information about the disks on a system.
Select an operation to perform: list
Menu:: VolumeManager/LVM_Conversion/ListDisk
Use this menu operation to display a list of disks. You can
also choose to list detailed information about the disk at a
Enter disk device or "all"[<address>,all,q,?](default: all) all
Device to list in detail [<address>,none,q,?] (default: none)
The DEVICE column shows the disk access names of the physical disks. If a disk has a disk media name entry in the DISK column, it is under VM control, and the GROUP column indicates its membership of a disk group. The STATUS column shows the availability of the disk to VxVM. LVM disks are displayed in the error state as they are unusable by VxVM.
To list LVM volume group information, use the listvg operation:
Select an operation to perform: listvg
List LVM Volume Group information
Menu:: VolumeManager/LVM_Conversion/ListLVMVolumeGroups
Use this menu operation to display a list of LVM volume Groups.
You can also choose to list detailed information about the LVMVG
at a specific disk device address.
Enter Volume Group (i.e.- vg04) or "all"
[<address>,all,q,?] (default: all)
vg02 Non-Root /dev/sdf /dev/sdh1
Volume Group to list in detail
[<address>,none,q,?] (default: none) vg02
Free PE / Size 4338 / 16.95 GB
VG UUID IxlERp-poi2-GO2D-od2b-G7fd-3zjX-PYycMn
--- No logical volumes defined in "vg02" ---
PV Status available / allocatable
Total PE / Free PE 2169 / 2169
PV Status available / allocatable
/dev under directories named for the volume group. VxVM create device nodes in /dev/vx/dsk/diskgroup and /dev/vx/rdsk/diskgroup. After conversion is complete, the LVM device nodes no longer exist on the system.
For file systems listed in /etc/fstab, vxvmconvert substitutes the new VxVM device names for the old LVM volume names, to prevent problems with fsck, mount, and other such utilities. However, other applications that refer to specific device node names may fail if the device no longer exists in the same place. Examine the following types of application to see if they reference LVM device names, and are at risk:
1 Analyze LVM Volume Groups for Conversion from the vxvmconvert main menu to see if conversion of each LVM volume group is possible.
This step is optional. Analysis can be run on a live system while users are accessing their data. This is useful when you have a large number of groups and disks for conversion to allow for the optimal planning and management of conversion downtime.
The following is sample output from the successful analysis of a volume group:
Volume Manager Support Operations
Menu:: VolumeManager/LVM_Conversion
1 Analyze LVM Volume Groups for Conversion
2 Convert LVM Volume Groups to VxVM
listvg List LVM Volume Group information
?? Display help about the menuing system
Select an operation to perform: 1
Analyze one or more LVM Volume Groups
Menu:: VolumeManager/LVM_Conversion/Analyze_LVM_VGs
Use this operation to analyze one or more LVM Volume Groups for
possible conversion to VxVM disk groups. This operation checks
for problems that would prevent the conversion from completing
successfully. For example, it calculates the space required to
add an LVM Volume Group's disk's to a VxVM disk group and
to replace any existing LVM partitions and volumes with VxVM
Volume Manager volumes, plexes, and sub-disks.
For this release, conversion is only allowed for Non-root LVM
Volume Groups. Hence, analysis is only allowed on Non-root LVM
More than one Volume Group or pattern may be entered at the
Here are some LVM Volume Group selection examples:
all: analyze all LVM Volume Groups (all except Root VG)
listvg: list all LVM Volume Groups
vg_name: a single LVM Volume Group, named vg_name
<pattern>: for example: vg04 vg09 vg08
Select Volume Groups to analyze:
[<pattern-list>,all,list,listvg,q,?] vg02
Analyze this Volume Group? [y,n,q,?] (default: y) y
Conversion Analysis of the following devices was successful.
Second Stage Conversion Analysis of vg02
Volume Group vg02 has been analyzed and prepared for conversion.
If off-disk data migration is required because there is insufficient space for on-disk data migration, you are prompted to select additional disks that can be used.
The analysis may fail for one of a number of reasons.
See "Volume group conversion limitations" on page 528.
The messages output by vxvmconvert explain the type of failure, and detail actions that you can take before retrying the analysis.
See "Examples of second stage failure analysis" on page 538.
Before running vxvmconvert, you can use the vgcfgbackup utility to save a copy of the configuration of an LVM volume group, as shown here:
# vgcfgbackup volume_group_name
This creates a backup file, /etc/lvmconf/volume_group_name.conf. Save this file to another location (such as off-line on tape or some other medium) to prevent the conversion process from overwriting it. If necessary, the LVM configuration can be restored from the backup file.
The vxvmconvert utility also saves a snapshot of the LVM configuration data during conversion of each disk. This data is saved in a different format from that of vgcfgbackup, and it can only be used with the vxvmconvert program. With certain limitations, you can use the data to reinstate the LVM volumes after they have been converted to VxVM. Even though vxvmconvert provides this mechanism for backing up the LVM configuration, you are advised to use vgcfgbackup to save the LVM configuration information for each LVM volume group.
Before performing a backup of the user data, note that backup procedures may have dependencies on the volume names that are currently in use on your system. Conversion to VxVM changes the volume names. You need to understand the implications that such name changes have for restoring from any backups that you make.
vxvmconvert attempts to unmount mounted file systems before starting conversion. However, it makes no attempt to stop applications that are using those file systems, nor does it attempt to deal with applications such as databases that are running on raw LVM volumes.
The LVM logical volumes to be converted must all be available to the vxvmconvert process. Do not deactivate the volume group or any logical volumes before running vxvmconvert.
You can use the following command to activate a volume group:
vxvmconvert main menu. The volume group is analyzed to ensure that conversion is possible. If the analysis is successful, you are asked whether you wish to perform the conversion.
Convert one volume group at a time to avoid errors during conversion.
The following is sample output from a successful conversion:
Volume Manager Support Operations
Menu:: VolumeManager/LVM_Conversion
1 Analyze LVM Volume Groups for Conversion
2 Convert LVM Volume Groups to VxVM
listvg List LVM Volume Group information
?? Display help about the menuing system
Select an operation to perform: 2
Convert one or more LVM Volume Groups
Menu:: VolumeManager/LVM_Conversion/Convert_LVM_VGs
Use this operation to convert LVM Volume Groups to VxVM disk
This adds the disks to a disk group and replaces existing LVM
volumes with VxVM volumes. LVM-VxVM Volume Group conversion
may require a reboot for the changes to take effect. For this
More than one Volume Group or pattern may be entered at the
Here are some LVM Volume Group selection examples:
all: convert all LVM Volume Groups (all except Root VG)
listvg: list all LVM Volume Groups
vg_name: a single LVM Volume Group, named vg_name
<pattern>: for example: vg04 vg08 vg09
Select Volume Groups to convert:
[<pattern-list>,all,list,listvg,q,? vg02
Convert this Volume Group? [y,n,q,?] (default: y) y
Conversion Analysis of the following devices was successful.
Second Stage Conversion Analysis of vg02
Volume Group vg02 has been analyzed and prepared for conversion.
Are you ready to commit to these changes?[y,n,q,?](default: y) y
vxlvmconv: making log directory /etc/vx/lvmconv/vg02.d/log.
vxlvmconv: starting conversion for VG "vg02" - Thu Feb 26
vgchange -- volume group "vg02" successfully deactivated
vxlvmconv: checking disk connectivity
Starting Conversion of vg02 to VxVM
vxlvmconv: Conversion complete.
Convert other LVM Volume Groups? [y,n,q,?] (default: n)
If off-disk data migration is required because there is insufficient space for on-disk data migration, you are prompted to select additional disks that can be used.
list operation in vxvmconvert to examine the status of the converted disks, as shown in this example:
Select an operation to perform: list
Menu:: VolumeManager/LVM_Conversion/ListDisk
Use this menu operation to display a list of disks. You can
also choose to list detailed information about the disk at a
Enter disk device or "all"[<address>,all,q,?](default: all) all
Device to list in detail [<address>,none,q,?] (default: none)
The LVM disks that were previously shown in the error state are now displayed as online to VxVM.
You can also use the vxprint command to display the details of the objects in the converted volumes (the TUTIL0 and PUTIL0 columns are omitted for clarity):
TY NAME ASSOC KSTATE LENGTH PLOFFS STATE
TY NAME ASSOC KSTATE LENGTH PLOFFS STATE
v stripevol gen ENABLED 1638400 - ACTIVE
pl stripevol-01 stripevol ENABLED 1638400 - ACTIVE
sd vg0102-01 stripevol-01 ENABLED 819200 0 -
sd vg0101-01 stripevol-01 ENABLED 819200 0 -
TY NAME ASSOC KSTATE LENGTH PLOFFS STATE
v concatvol gen ENABLED 163840 - ACTIVE
pl concatvol-01 concatvol ENABLED 163840 - ACTIVE
sd vg0202-02 concatvol-01 ENABLED 163840 0 -
v stripevol gen ENABLED 81920 - ACTIVE
pl stripevol-01 stripevol ENABLED 81920 - ACTIVE
sd vg0202-01 stripevol-01 ENABLED 40960 0 -
sd vg0201-01 stripevol-01 ENABLED 40960 0 -
vxvmconvert, remount them using their new volume names. The vxvmconvert utility automatically remounts any file systems that were left mounted.
mydg, its disks are assigned names such as mydg01, mydg02, and so on. Plexes within each VxVM volume are named mydg01-01, mydg01-02, and so on. If required, you can rename disks and plexes.
See "Renaming a disk" on page 136.
See "Changing plex attributes" on page 243.
Only rename VxVM objects in the converted disk groups when you are fully satisfied with the configuration. Renaming VxVM objects prevents you from using vxvmconvert to restore the original LVM volume groups.