add logical volume and add chunk on informix without package halt

[Tapas Jha]

Is it possible to add logical volume or to add chunk on Informix on cluster environment without halting package or without halting cluster?

I have two queries on cluster environment. We have MCserviceguard.

First, I want to create one chunk on Informix. For that I need to create one logical volume and then link the corresponding raw logical volume to /dev/informix/.

Example given below are for adding chunk of 1GB.

Create one logical volume under /dev/vg02 using lvcreate. Suppose it create lvol40 and rlvol40 in /dev/vg02

brw-r----- 1 root sys 64 0x020028 Dec 22 2005 ../vg02/lvol40

crw-rw---- 2 informix informix 64 0x020028 Dec 22 2005 ../vg02/rlvol40

create a link on /dev/informix directory named shipdetails.sis.

crw-rw---- 2 informix informix 64 0x020028 Dec 22 2005 shipdetails.sis

make ownership as Informix:Informix and change permissions as 660.

The same thing should be present on other node of cluster.

root:/dev/vg02# brw-r----- 1 root sys 64 0x020028 Dec 22 2005 lvol40
crw-rw---- 2 informix informix 64 0x020028 Dec 22 2005 rlvol40

root:/dev/vg02#

root:/dev/informix1# ll|grep 20028

crw-rw---- 2 informix informix 64 0x020028 Dec 22 2005 shipdetails.sis

Secondly, I want to create one 1GB File system. For that I need to create 1GB lvol using lvcreate on one node and same thing I need to export on other node. To make online I need to put on package script files on both nodes.

Can both the process be possible without letting package down/halt? It would be of great help if you can provide me solution with a procedure.

Regards
Tapas

[Steven E. Protter]

Shalom Tapas,

Yes.

If you don't have Online JFS fail the whole application to the node you are NOT working on.

Then you can umount any filesystems and properly extend any raw disk areas using Informix utilities without disrupting the cluster.

SEP

[nanan]

yes or not

The VG02 is shared volume, isn't it?
If OK, you can not add lvol to vg20 with out package halt

IF not, you can

The second one is possible in the package runing.

[Tapas Jha]

Nanan and Protter,
Thanks for your reply.

I think for cluster volume group will be on shared, by default.

My questions are like below. Would you kindly elaborately reply?
Q1) Can i add logical volume when cluster and package is up and running?
Q2) If yes, do i need to halt package?
Q3) Can i add logical volume and then add Filesystem without halting package?
Q4) Can i add logical volume and then can i add raw volume(rlvol..) to the database and for that i don't need to halt package?
Q5) For all of the above, what is the process?

I can understand that my questions are looks like same in some cases.

With regards
Tapas

[freddy_21]

informix using raw devices right? so i think no changes at your cluster configuration, but you need update lvm configuration

thanks
freddy

[Steve Lewis · Accepted solution]

"I think for cluster volume group will be on shared, by default."

- No it won't be Shared Mode VG activation with informix, more likely active/passive. If vgdisplay says 'Exclusive' and your package control script says vgchange -a e then it isn't shared. Apart from that, shared mode is only supported with Oracle, not informix. The storage must be visble to both nodes.

My questions are like below. Would you kindly elaborately reply?
Q1) Can i add logical volume when cluster and package is up and running?

Yes - but only on the node you are running on. You will have to copy the configuration to the other node at some point.

Q2) If yes, do i need to halt package?

-No not immediately. At some point you have to copy the config over to the other node, hopefully before the system crashes. The best solution is to do it all at once, with the cluster down. If it is urgent, then vgexport -p and copy the device files, package file over immediately, then shut down the package and update/test the other node later,

Q3) Can i add logical volume and then add Filesystem without halting package?

-Yes, but only on the current node. See above.

Q4) Can i add logical volume and then can i add raw volume(rlvol..) to the database and for that i don't need to halt package?

- Yes, as above. But you should use a symbolic link within the database, not the actual raw logical volume or cooked filename.

Q5) For all of the above, what is the process?

First check your informix storage. Is it cooked files? You said filesystem but then talked about raw logical volumes which makes me wonder how much you know.
When you have increased the space on the active node, you must negotiate a suitable moment to halt the package, vgexport your volume groups in PREVIEW MODE, copy the device files over to the other node (I use tar for this), make sure you see the disk device files on the other node and work out what they are called, vgimport, check/edit your package file. Any new volume groups should be added to the cluster, which is a cluster re-build.
You obviously don't need to add the chunks to both nodes because informix stores all this internally on the shared disk.

The most important thing of all is to re-test your cluster start-up on the passive node and then again on the active node.

[Tapas Jha]

Thanks Freddy and Steve Lewis,
yes informix use raw logical volume as i already mentioned on my initial questions. I have two questions, one for File System and other for database(informix). I have not mixed anything. I need to know if urgency comes to give space for F.S and if more chunks needs to be added then should i halt package or not. Thanks for your valuable inputs.
Informix will not take care automatically if packages moves to other nodes. For that you need to vgexport, ftp to other node, vgimport and then create a link on /dev/informix with the same name as given to first node.