Cluster - Add/Change Logical Volume

[Nikee Reddy]

Hello,

Our production systems are running in a cluster environment.

Primary System name: Orion (Pkg is up& running)
Fail-Over system name: europa

We have a volume group: vgdb6 and it has 2 logical volumes. Both the logical vomues are full.

I still have free space in the volume group.

In a Cluster environment:--------
1. Can increase the existing logical volume sizes?
If so, do I have do make any changes on both the servers?


2. If the above case not possible, can I create a new logical volume in the volume group?
If so, do I have do make any changes on both the servers?


Here is the VG info:
--- Volume groups ---
VG Name /dev/vgdb6
VG Write Access read/write
VG Status available, exclusive
Max LV 255
Cur LV 2
Open LV 2
Max PV 255
Cur PV 1
Act PV 1
Max PE per PV 15000
VGDA 2
PE Size (Mbytes) 128
Total PE 703
Alloc PE 270
Free PE 433
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Logical volumes ---
LV Name /dev/vgdb6/data67
LV Status available/syncd
LV Size (Mbytes) 17280
Current LE 135
Allocated PE 135
Used PV 1

LV Name /dev/vgdb6/data68
LV Status available/syncd
LV Size (Mbytes) 17280
Current LE 135
Allocated PE 135
Used PV 1


--- Physical volumes ---
PV Name /dev/dsk/c15t0d2
PV Status available
Total PE 703
Free PE 433
Autoswitch On


Thank you,
Nikee

[Nikee Reddy]

Hello,

Here is the LV info:

--- Logical volumes ---
LV Name /dev/vgdb6/data67
VG Name /dev/vgdb6
LV Permission read/write
LV Status available/syncd
Mirror copies 0
Consistency Recovery MWC
Schedule parallel
LV Size (Mbytes) 17280
Current LE 135
Allocated PE 135
Stripes 0
Stripe Size (Kbytes) 0
Bad block NONE
Allocation strict
IO Timeout (Seconds) default

--- Distribution of logical volume ---
PV Name LE on PV PE on PV
/dev/dsk/c15t0d2 135 135

--- Logical extents ---
LE PV1 PE1 Status 1
00000 /dev/dsk/c15t0d2 00000 current
00001 /dev/dsk/c15t0d2 00001 current
00002 /dev/dsk/c15t0d2 00002 current
00003 /dev/dsk/c15t0d2 00003 current
00004 /dev/dsk/c15t0d2 00004 current


Thank you,
Nikee

[A. Clay Stephenson · Accepted solution]

You can increase the LVOL "on the fly" (assuming that you have OnlineJFS) and once done on the active node that is the only change needed. If the package moves to another node then all the data are stored in the LVM reserved areas of the disks and the new node will "see" these changes without any additional action on your part.

No need to answer question 2 since question 1 is "yes".

[James R. Ferguson]

Hi Nikee:

Yes, you can increase ('lvextend') the logical volumes and the filesystems they contain on one node and do nothing on the other.

Regards!

...JRF...

[Nikee Reddy]

Thank you All,

Can you please let me know the command to extend the logical volumes?

Thank you,
Nikee

[James R. Ferguson]

Hi (again) Nikee:

The command to extend a logical volume is 'lvextend'.

See the manpages for more information.

Since you ask that, however, I suspect that it would be safer for use to use SAM to enlarge the logical volume and the filesystem that resides in it.

Regards!

...JRF...

[Doug O'Leary]

Hey;

Hopefully, this link will give you some useful information...

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

Doug O'Leary

[Bharat Katkar]

Hi Nikke,
If its a Online JFS command is "fsadm".
See man fsadm for more details.
In case if it is not an Online JFS then you will have to unmount the filesystem first.

# umount
# lvextend -L -n

Cross check the options again by:
# lvextend -h

Then you can simply remount it and check the extended size by "bdf".

Regards,

[Chauhan Amit]

For Case 2 - If you are creating a new logical volume , given below are the instructions:

Adding or removing an logical volume (lvol) or file system to/from a cluster VG - The device special files of new lvols need to be created on all other cluster nodes,those of removed lvols need to be deleted. This may be done with mknod/rmsf,however it is recommended to perform the Re-Import VG Procedure below.Additionally the package control scripts need to be adapted on all nodes to reflect the new configuration. Mount points need to be created for new file systems.

The Re-Import VG Procedure

We assume that a cluster volume group /dev/vg01 with VG group special file minor number 0x010000 needs to be re-imported.

Steps for the node that has the VG active:

1. Create a mapfile:
node1# vgexport â v â p â s â m /tmp/vg01.map vg01
Warning messages indicating that the VG is active should be ignored.

2. Copy mapfile to each of the other cluster nodes (using for example rcp, ftp, etc.)
node1# rcp /tmp/vg01.map node2:/tmp/vg01.map
...

Steps to be performed on each of the other nodes:

3. Note VG minor number and permissions/ownership:
node2# ll /dev/vg01
total 12
drwxr-xr-x 2 root root 1024 Apr 16 12:04 ./
dr-xr-xr-x 19 bin bin 5120 Jun 20 06:44 ../
crw-r----- 1 root sys 64 0x010000 Apr 4 13:32 group
brw-r----- 1 root sys 64 0x010001 Apr 4 13:32 lvol1
crw-r----- 1 root sys 64 0x010001 Apr 4 13:32 rlvol1

4. Export the VG:
node2# vgexport vg01

5. Re-create VG directory:
node2# mkdir /dev/vg01

6. Re-create VG group special file, use minor number noted above.
node2# mknod /dev/vg01/group c 64 0x010000

7. Run vgimport using the copied mapfile:
node2# vgimport â v â s â m /tmp/vg01.map vg01

-Amit