lvcreate in Cluster aware vg of package without pkghalt

[HP-UX admin]

Hi,
Is it possible to lvcreate in Cluster aware vg of the package without doing pkghalt.So that adoptive node will aware of this LV.
Can I do it Online without halting Package or Cluster.
thanks.

[sajeer_2]

NO.You have to shutdown package.

You have the following steps

Halt package
In the primary node,
vgchange -a e /dev/vgXX
lvcreate -L sizeinMB -n name /dev/vgXX
vgexport -p -v -s -m vgXX.map /dev/vgXX
rcp vgXX.map node2:/vgXX.map

In other nodes,you have to export the vgXX configuration and import it.
vgexport /dev/vgXX
mkdir /dev/vgXX
mknod /dev/vgXX/group c 64 0x020000
vgimport -v -s -m /vgXX.map

Regards,
Sajeer

[Frank de Vries]

No you can do it perfectly online.

Please note in the previous answer
there is a contradiction.

(I have removed the halt pkg instruction)

In the primary node,
vgchange -a e /dev/vgXX
lvcreate -L sizeinMB -n name /dev/vgXX
vgexport -p -v -s -m vgXX.map /dev/vgXX
rcp vgXX.map node2:/vgXX.map

In other nodes,you have to export the vgXX configuration and import it.
vgexport /dev/vgXX
mkdir /dev/vgXX
mknod /dev/vgXX/group c 64 0x020000
vgimport -v -s -m /vgXX.map

Another remark:

It is a good idea to to a ls -lR > log.lst of the/dev/vgXX so you have a list of
all the minor node id's

[Gerardo Mora]

Hi,

I'm agree with Frank, I do that job periodically and it works fine, but also I have to add the new logical volume in package_name.ctrl file and copy that file to all nodes in the cluster.

[Kevin Wright]

absolutely. Make sure the pkg control file is updated with your new lvol. vgexport/vgimport the VG.

Test at your next maint. window.

[Kasper Hedensted]

You could test it right away on the adoptive node:

vgchange -a r
mount filesystem
umount filesystem
vgchange -a n

remember to "vgchange -a n" or else the package will not be able to failover at later time.

Cheers,
Kasper

[Geoff Wild]

Yes you can do it online!

See table 7.1:

http://docs.hp.com/en/B3936-90079/ch07s04.html

After that, you have to create a new map file on that node
vgexport -p -s -v -m /tmp/vgXX.map /dev/vgXX

copy that to adotive node,

on adoptive node, make note of the minor number:

ll /dev/vgXX/group

vgexport /dev/vgXX
mkdir /dev/vgXX
mknod /dev/vgXX/group c 64 0xHH0000

vgimport -s -v -m /tmp/vgXX.map /dev/vgXX


NOTE: XX= number of your vg
HH = hex value of minor number..

Example - vg05 should have group file 0x050000
vg10 should have group 0x0a0000

Now that isn't mandatory - but trust me - you want it that way.


Rgds...Geoff

[HP-UX admin]

Thanks.

Some of u suggested to do vgchange -a e & add that LV in Package control script.
Why this is required?

[nanan]

Hi! admin
The main reason why you have to do vgchange -a e is that just you can create lvols exclusive mode, i mean you can't create shared mode.
Cluster wide volumes should keep consistency for the access so when you configure your cluster using exclusive file system, the system which is handling those cluster filesystems have to open the vgs to exclusive mode.

Anyway, you can create cluster vgs online without haltpkg.
As previous stated, you have to do vgexport and vgimport

but you can't create cluster package using shared mode

Regards
nanan

[Stephen Doud]

If vgdisplay reports the status of the VG as:
available, exclusive
then it is possible to lvcreate a new volume in the VG while the package is running.
In order to know what must be done on a Serviceguard cluster to accommodate the lvcreate, you need to know that lvcreate modifies the VGDA (LVM structures on the disk) and does a couple of mknod's in the /dev/ directory. lvcreate does not modify the /etc/lvmtab file.
Once the new logical volume is created, you probably want to create a file system in i, and have the package control script mount it - correct?
Therefore, the following is necessary as a result of the lvcreate:
1) On the node where the lvcreate was performed, newfs a file system on the new lvol
2) Edit the package control script to reference the new file system, and copy the update to the other node.
3) On the other node, update /dev/ by either manually performing the mknod's to duplicate the new lvol/rlvol pair, or vgexport and re-import (vgimport) the VG.

All of this can be done while the VG is active and operating under control of Serviceguard, in a package.