topic Re: Extend a VG online, with online JFS in Operating System - HP-UX

Extend a VG online, with online JFS

N Ward — Fri, 07 Aug 2009 13:00:38 GMT

Hi, we have a plan to extend a redo log area in a Production Cluster (Primary, Standby setup). The LUN has been presented and we are ready to do the work.

Because we have online JFS I can do the vgextend, lvextend and fsadm online with no interruption, however what about letting the standby node know about the new PV in the volume group? I can't import on the secondary node without stopping the primary.. Is there a way to make sure the Standby node is aware of the PV for failover?

Re: Extend a VG online, with online JFS

Sunny123_1 — Fri, 07 Aug 2009 13:14:08 GMT

Hi

Just import the VG on secondary node.It is the good way to Standby node to avare of PV for failover

Regards
Sunny

Re: Extend a VG online, with online JFS

Rita C Workman — Fri, 07 Aug 2009 13:19:36 GMT

When you say vgextend...you are implying you are adding new disk. Otherwise you'd just be lvextending.

So, make sure that your secondary nodes can "see" the new disk. i.e. the new disk is masked to the secondary nodes.

Do your extend on the primary production server, and create new mapfiles for the volume group.
Then as was just mentioned, do the vgimport steps on the secondary nodes.
i.e. vgexport /dev/vgname
mkdir /dev/vgname
mknod /dev/vgname/group c 64 0x--0000
vgimport -vs -m /etc/lvmconf/vgname. /dev/vgname

Regards,
Rita

Re: Extend a VG online, with online JFS

Ganesan R — Fri, 07 Aug 2009 13:42:59 GMT

Hi,

>>>I can't import on the secondary node without stopping the primary.<<<<

Why do you think so? If the lun is presented to both the nodes, you can take the map file by exporting the VG in preview mode and import the vg information on standby node using the map file.

No need to down the primary to take the map file. Just export the vg in preview mode. Preview mode does not export the vg. It just creates the map file.

Re: Extend a VG online, with online JFS

N Ward — Fri, 07 Aug 2009 14:14:37 GMT

Thanks, I was just concerned that I couldn't import on the Secondary node without the Primary being exported. I guess thats not the case.

So map file created on Primary (with export) and copied over to Secondary node where the import is run. Primary is not affected by this.

Re: Extend a VG online, with online JFS

Lijeesh N G_1 — Fri, 07 Aug 2009 14:17:32 GMT

Hi,

You can do it without stopping the primary node,but note that, ensure you are
exporting/Importing the VG in ***preview mode***. Steps are follows,

1) Ensure the LUN is visible and accessable from both the nodes.
2) Extend the VG in Node1.
3) Export the VG configuration in preview mode,
#vgexport -p -s -m
4) Copy to Node2.
#scp Node2:/tmp
5) Import VG in Node2 in preview mode
#vgimport -p -s -m

Regards,
LIJEESH N G

Re: Extend a VG online, with online JFS

Sunny123_1 — Fri, 07 Aug 2009 14:18:58 GMT

Hi

Yes you are right Ward.

Regards
Sunny

Re: Extend a VG online, with online JFS

N Ward — Fri, 07 Aug 2009 14:21:23 GMT

Thanks all, its clear now...

Re: Extend a VG online, with online JFS

N Ward — Fri, 14 Aug 2009 07:28:45 GMT

Having just carried out this work. When importing on the Secondary node the /etc/lvmtab hasn't been populated, how will node two know aobut the devices ( or how will I get it know about them? )

Re: Extend a VG online, with online JFS

Michal Kapalka (mikap) — Fri, 14 Aug 2009 07:32:46 GMT

hi,

Having just carried out this work. When importing on the Secondary node the /etc/lvmtab hasn't been populated, how will node two know aobut the devices ( or how will I get it know about them? )

the disks( LUNS ) must be presented on both nodes, and if you are using the vgexport with the -s option them the vgimport will be made with the vgid.

of course you need to make ioscan and them insf to see the special files on the server.

mikap

Re: Extend a VG online, with online JFS

Ganesan R — Fri, 14 Aug 2009 07:34:00 GMT

Hi Again,

I suspect that you have imported in preview mode on secondary. is it?

You have to import it in normal mode not the preview mode.

#vgimport -v -s -m vgname

Re: Extend a VG online, with online JFS

Stephan. — Fri, 14 Aug 2009 07:37:57 GMT

Hi,
you will need to add it manually.

Re: Extend a VG online, with online JFS

N Ward — Fri, 14 Aug 2009 07:52:05 GMT

ioscan and insf been done, tried it in preview and 'proper' mode (without the -p) and still nothing extra in /etc/lvmtab. Output says "Beginning import... blah blah" then "Volume group already in /etc/lvmtab"

Re: Extend a VG online, with online JFS

Michal Kapalka (mikap) — Fri, 14 Aug 2009 07:56:20 GMT

hi,

of couse because the vg is there alredy.

the cluster was configured a nd the vg was imported to both nodes.

mikap

Re: Extend a VG online, with online JFS

Ganesan R — Fri, 14 Aug 2009 08:00:05 GMT

Hi,

>>>Output says "Beginning import... blah blah" then "Volume group already in /etc/lvmtab"<<<

As per this message, vg is already there in lvmtab file.

Can you post the volumegroup names you are trying to import and #strings /etc/lvmtab output from secondary node ?

Re: Extend a VG online, with online JFS

N Ward — Fri, 14 Aug 2009 08:00:22 GMT

"of couse because the vg is there alredy.

the cluster was configured and the vg was imported to both nodes"

I'm aware of this, I was just providing the text output, but that is all I get, /etc/lvmtab does not get updated.

Re: Extend a VG online, with online JFS

Michal Kapalka (mikap) — Fri, 14 Aug 2009 08:05:07 GMT

ok check if the vg that you like to import is in the /etc/lvmtab.

mikap

Re: Extend a VG online, with online JFS

N Ward — Fri, 14 Aug 2009 08:10:58 GMT

"ok check if the vg that you like to import is in the /etc/lvmtab"

It is already there, with the unextended set of devices..

I can get a strings of /etc/lvmtab off but it will take a while due to the nature of the system.

Re: Extend a VG online, with online JFS

Ganesan R — Fri, 14 Aug 2009 08:17:54 GMT

Hi,

If you are not providing the output we asked, it is little difficult to help you out. We are interacting through forum. So it is not possible to understand the issue correctly unless you provide all the necessary details.

ok. back to your reply.
>>"of couse because the vg is there alredy.
the cluster was configured and the vg was imported to both nodes"<<

Does current lvmtab file has entry about the vg or not? Or provide the exact steps you followed starting from exporting on primary node to importing on alt node.

Re: Extend a VG online, with online JFS

N Ward — Fri, 14 Aug 2009 08:40:20 GMT

Hi I appreciate the help and I haven't said I won't get the input, I'm just explaining that its difficult due to the security of the system.

Yes, the vg is in the /etc/lvmtab on both nodes. On the Primary node it has the newly added devices too, on the Standby node following the import, it does not have the extended devices.

I will try and get the info off and update the forum later.

Process followed..

Extend VGs on Primary, extend LVs, fsadm on mount points. Create map file

# vgexport -p -s -m /tmp/redo1.map /dev/vg_ora_coredb_redo1

Copy map file to Secondary node.
ioscan and insf -e on secondary node.

# vgimport -s -m -v /tmp/redo1.map /dev/vg_ora_coredb_redo1