Add an lvol on MCSG

[iranzo]

Hello,
On a two node cluster HPUX,
we have vg01 on one pakcage,
we want to add an lvol (LVM) on vg01,
we look for sequence of operation
(lvextend,vgexport...),cluster config
modification.
How can we start and stop a new process
on this package ?
Thank's a lot.

[G. Vrijhoeven]

Hi,

If you have enough space in the vg, this van be the right order.

1. lvcreate ( lvextend increases size, does not add lvol) on the active cluster node. Do a mkdir ( mountpoint )and a newfs on the lvol
and do a vgcfgbackup

2. Adjust the control file by addin the lvol.
Mind the Numbers.

3. Export the vg ( vgexport -p -m mapfile -f devfile vgname)

4. mkdir on remote servers and copy the cntl file to all servers

5. vgimport the map and dev file on all servers. ( mind the device files, they can differ on other servers.) vgchange -a r && vgcfgback vname && vgchange -a n vgname


HTH,

Gideon

[G. Vrijhoeven]

Sorrie,

forgot the mount part. mount lvol after step 1.

HTH,

Gideon

[jpcast_real]

Just a poing

If you make the vgexport with the "-s" option you will not need to take care of the device files . It will just look for the disks which has the VGID. In the "Managing serviceguard" manual you will find the detailed procedure..

[jpcast_real]

I send you the following document

How do I add a new disk to a ServiceGuard volume group and package?

RESOLUTION
NOTE: Most of the work in this document is LVM-based. Should an error occur
during an LVM command, consult the ITRC.HP.COM technical knowledge base
documents for assistance.

From time to time it becomes necessary to add a disk to a volume group in a
package of a ServiceGuard cluster. This document gives the step--by-step
treatment to that process.

1a. Select an unused disk to add to the volume group (VG).

NOTE: At this time, SAM is unable to determine if a deactivated disk is
in use on another system. It can mistakenly allow you to allocate the disk
again on a system that doesn't yet claim the disk. BE AWARE BEFORE YOU
SHARE.

Use SAM:
Disks & File Systems -> Volume Groups -> Select a Disk

OR

1b. LVM will allow you to extend a physical volume into a VG whether or not the
VG is active. WARNING: INSURE THE DISK IS NOT ALREADY ALLOCATED TO
ANOTHER VOLUME GROUP IN ANOTHER CLUSTER!
On the node where it is active, use this syntax:

Example:
# pvcreate -f /dev/rdsk/c4t4d0

If the disk has a PV-link (another path through another I/O adapter) and
I/O bus load balancing is also an issue, vgextend the disk's paths into
/etc/lvmtab in the order that LVM should access them:

# vgextend vg07 /dev/dsk/c4t4d0
# vgextend vg07 /dev/dsk/c2t4d0

An alternative to this method of setting the primary path is the pvchange
command:

# pvchange -s /dev/dsk/c2t4d0


2. On the same node, add logical volumes to the volume group as needed, or
extend current logical volumes.
NOTE - Online JFS is required to extend logical volumes that are
active.

Example:
# lvcreate -L 600 vg07 (creates a 600MB logical volume)
# newfs -F vxfs /dev/vg07/rlvol1 (if not a raw database lvol)

Mount the new lvol:

# mount /dev/vg07/lvol1 /data7

Load the new lvol with data as needed. Umount it when complete.

3. On the same node, create a new map file:

Example:

# vgexport -pvs -m /etc/lvmconf/vg_shared.map /dev/vg_shared

NOTE: the -s option adds the unique VGID to the top of the map file. It
will be used by the vgimport process to identify disks labeled with this
VGID, to eliminate the need to specify the actual physical disks to import.
The -s option is NOT available with HP-UX 10.01. In that case, you must
explicitly list every disk that belongs to the volume group during the
vgimport.

4. Copy the map file to the other adoptive node(s)

Example:
# rcp /etc/lvmconf/vg_shared.map nodeB:/etc/lvmconf

5. On the adoptive node that doesn't have the VG activated, record the group
minor number for the VG to which you added the disk.

# ll /dev/vg*/group
crw-r----- 1 root root 64 0x000000 Sep 19 1996 /dev/vg00/group
crw-rw-rw- 1 root sys 64 0x020000 Jun 4 12:39 /dev/vg07/group
^
Record eg:0x02 <--

6. On the adoptive nodes where the VG is not active, vgexport the volume group:

Example:

# vgexport /dev/vg07

It will remove /dev/vg07 and all special files in it.

7. Recreate the directory and group file:

Example: Note: from step 5
|
# mkdir /dev/vg07 |
# mknod /dev/vg07/group c 64 0x020000

8. Reimport the VG using the new map file.

Example:

# vgimport -vs -m /etc/lvmconf/vg07.map /dev/vg07

This command will cause LVM to query ALL PV's (Physical disks) on the
system, inspecting them for a VGID that matches the one listed in the top of
the map file. It adds all matching disks into the /etc/lvmtab. It also
adds new lvols. If you want your pvlinks listed in a particular order, do
NOT use the -s option, but individually specify the sequence of disks.

9. On the original node, update the package control script with the additional
lvols and mountpoints and distribute the control script to all adoptive
nodes.

Example listing of lines added in the control script. Note the sequentially
increasing array index numbers :

LV[0]="/dev/vg06/lvol1"; FS[0]="/vg06/lvol1_mount"
LV[1]="/dev/vg06/lvol2"; FS[1]="/vg06/lvol2_mount"
LV[2]="/dev/vg07/lvol1"; FS[2]="/vg07/lvol4_mount"
LV[3]="/dev/vg07/lvol2"; FS[3]="/vg07/lvol5_mount"
LV[4]="/dev/vg07/lvol3"; FS[4]="/vg07/lvol6_mount"
LV[5]="/dev/vg07/lvol4"; FS[5]="/vg07/lvol7_mount"
\ \
Note the index numbers don't start at zero since this particular disk added
more mount points in the VG

10. Test the new logical volume actuation on all adoptive nodes by restarting
the package on all nodes.

### END ###

[Printaporn_1]

Hi,

Please be very carefull on shared disk.
make sure that those device files is not used and mount on another node.