Automatic activation of shared VG

[Christian Lafleur]

Hi,

I use shared VG (on 2 nodes) with ServiceGuard...

If i reboot an node, VG is not activated automatically ...

AUTO_VG_ACTIVATE=1 in /etc/lvmrc


how i can assure automatic VG activation in case of unwanted reboot ?

thanks

[A. Clay Stephenson · Accepted solution]

Under MC/SG, you do not want AUTO_VG_ACTIVATE=1 because all shard VG's should be under the control of their MC/SG package scripts. The unshared VG's on each node should be added to the custom_vg_activation function in /etc/lvmrc on each node.

Your current setting will cause the shared VG's to be activated by all the nodes and will lead to data corruption.

[Sanjay_6]

Hi Vasago,

you need to set "AUTO_VG_ACTIVATE" to "0" in the /etc/lvmrc file in the SG env. Since SG will activate its own vg using the package control script, you do not activate the SG vg's during system reboot.

Take a look at this doc from itrc,

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000072570238

The itrc doc id is UMCSGKBRC00010342.

Check the section related to /etc/lvmrc.

Also take a look at this doc for detailed reasoning,

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062686639

The itrc doc id is UXSGKBAN00000041.

Hope this helps.

Regds

[melvyn burnard]

well in a Serviceguard config, if the VG is one that you use for your package, you do NOT want it activated at boot time.
The package takes care of activating the VG's it requires when the package starts up on the node.
Any VG that is NOT part of a SG package needs to be added in at the custom_vg_activation portion.

[Christian Lafleur]

Well thanks to all.

I have tried this config. But Shared VG is not more active on reboot.

I need to have Active Shared VG on 2 nodes on the same time (VG server on one node and client on second node) bcause i use Oracle RAC with RAC option for SG. I dont need package.

Do i need to create package just for activate shared VG. ?
thanks

[Stephen Doud]

Yes - you need to create a package just to activate the shared VG, since it cannot be activated during boot time (the cluster daemons are not up an will not be available to authorize lvmkd to activate the VG).
Set the cluster to auto-form when the node boots:
/etc/rc.config.d/cmcluster: AUTOSTART_CMCLD=1
(on each node).

Caveat: If one node is not running Serviceguard, the other node will not form a one-node cluster and start the package.

[Geoff Wild]

Yes - create a package to mount the vg.

IMHO - I would not auto start the cluster on boot...

If a hardware failure - you will probably want to investigate prior to starting any applications - or, say you apply a pacth - which requies a reboot, or a kernel change - you may want to check system prior to starting up any applications....or you boot both boxes - but one starts up quicker then the other - your cluster may not form anyways...



Rgds...Geoff

[Steven E. Protter]

You say:
I need to have Active Shared VG on 2 nodes on the same time (VG server on one node and client on second node) bcause i use Oracle RAC with RAC option for SG. I dont need package.
<<
Thats a no no. If you try and activate a volume group containing the same disks on two machines at the same time, you will likely corrupt the data.

Serviceguard is a high availabilty system. It works like this:

Whichever node the package is running on needs to control the volume group. It activates it at start up.

Basically control of the volume group passes from node to node with the package. This is something you test when you test your cluster configuration.

You need to structure your packages for this operational format. Its the way SG works.

SEP