Luns and LVM

[Joakim Rudén]

Hi .
I've created one lun which is mapped to 2 servers : server A och server B. Lun is on volymgroup on server A .
I extended that volume group on server A by using lxextend - l syntax and filesystem online
on server A
But I don't know if I have to do it the same on server B or not ?

SERVER A
stona01:/vol/cl_erp02/luns/lun01 (LUN 14)
2g (2147483648) lun state: GOOD
Filer_CF_State: Cluster Enabled Filer Partner: stona02
Multipath_Policy: None
Multipath_Provider: None
-------- --------- -------------------- ------ ------- --------
host filer primary partner
path path /dev/dsk host filer filer
state type filename HBA port port
-------- --------- -------------------- ------ ------- --------
up primary /dev/dsk/c33t1d6 td1 0d
up secondary /dev/dsk/c27t1d6 td1 0d
up primary /dev/dsk/c31t1d6 td0 0b
up secondary /dev/dsk/c23t1d6 td0 0b

****************************************

SERVER B
stona01:/vol/cl_erp02/luns/lun01 (LUN 14)
2g (2147483648) lun state: GOOD
Filer_CF_State: Cluster Enabled Filer Partner: stona02
Multipath_Policy: None
Multipath_Provider: None
-------- --------- -------------------- ------ ------- --------
host filer primary partner
path path /dev/dsk host filer filer
state type filename HBA port port
-------- --------- -------------------- ------ ------- --------
up primary /dev/dsk/c33t1d6 td1 0d
up secondary /dev/dsk/c22t1d6 td1 0d
up primary /dev/dsk/c31t1d6 td0 0b
up secondary /dev/dsk/c9t1d6 td0 0b


Thanks for any advice

[Rita C Workman]

I'm having a bit of difficulty figuring out exactly what you want. Appears to be a language translation confusion. I'm thinking your looking at a clustered enviroment maybe.

But...if you have 1 lun that you want to be seen by two servers. And you have mapped the 1 lun to both servers.
Then you only need to create the volume group and lvol and extend them on one of the servers.
Then you would run command vgexport -pvs -m //vgname.map /dev/vgname. Then take the mapfile it created and copy that to the second server and run:
mkdir /dev/vgname
mknod /dev/vgname/group c 64 0x0000
vgimport -vs -m //vgname.map /dev/vgname

Now the second server has the volume group information, and should you need to access it, you would deactivate the volume group on server one - then activate the volume group on server two.

Hope that is what your looking for,
Rita

[P Arumugavel]

hi,

Your words pointed me to a cluster environment where the shared VG is the basic thing.

Do whatever changes you want in VG in server A. And export the map file of same VG in preview mode and copy into server B.
Create the VG directory and group file using the same minor number used in server A and import the VG information using the map file. Activate the volume group and get the access on server B.

Extend the thread if this is not exactly you looked for.

Rgds...

[Doug O'Leary]

Hey;

If you're simply extending an LV, then you won't have to export/import.

An old ll entry from when I initially took the MCSG class (almost 10 years ago now... ) shows when you have to import/export.

http://www.olearycomputers.com/ll/mcsg/mcsg_export.html

Hope that helps.

Doug O'Leary

[Alzhy]

Joakim,

I don't think you have to do anything on ServerB as you merely expanded an LVOL/Filesystem on Server A. When you failover the storage to Server B -- the import and mount will simply recognise the new size of the LV and the Filesystem on top/

You only need the vg map gyrations if you've added new LVOLs. In this case - you have merely expanded -- so I think all is good sir.