LVM

[Anjaneyulu]

Hi,

If we want to increase th FS. we add the LE to the lv.


I think PE is a combination of LE's.

Please send if you have any document regarding this.

[Eric SAUBIGNAC · Accepted solution]

Bonjour,

Try :

http://tldp.org/HOWTO/LVM-HOWTO/anatomy.html
http://docs.hp.com/en/6054/LVM_Limits_White_Paper_V4.pdf
man 7 lvm

HTH

Eric

[Ganesan R]

Hi Anjaneyulu,

If you want to increase the FS, first you should increase the underlying logical volume.

To increase the logical volume you should have free PE's in the volume group. check with #vgdisplay vgname to check free PE's. If no free PE's then you should add new disk/LUN to the vg.

>>I think PE is a combination of LE's.<<<

Not correct. PE is the smallest portion of physical disks. When it is assigned to LV it will be called as LE or you can say LE is mapping to PE.

[sujit kumar singh]

hi


as u want to increase the FS say /oracle which has the underlying LV as /dev/vg02/lvol2 say.
this u can get from the bdf command O/p.

now check if enough free PEs are availbale in the VG to which LV belongs. U can get the same form the vgdisplay -v /dev/vg02 O/p that will show u the available or Free PEs.
also look out for the PE Size for this VG.
the Free PE multiplied bt the PE Size that is specified in MB gives the free apce available in MB in the VG that u can use for the LV to extend.
IF u have Online JFS in the system then u can Extend the filesystem Online that is without the Application to be down which is accessing that LV.
if u have Online JFS installed that u can check with #swlist -l product | grep -i OnlineJFS go to step2 or follow step 1 that shall require the LV to be umounted.

1)stop the app that is accessing that FS, un mount this using #umount /oracle, #lvextend -L /dev/vg02/lvol2,extendfs -F vxfs /dev/vg02/rlvol2,mount /dev/vg02/lvol2 /oracle.

2)If u have OnlineJFS installed u can do this by #lvextend -L /dev/vg02/lvol2
,#fsadm -b /oracle

done.

so step2 shall help u do this without any downtime for application but u need OnlineJFS to do that wihout which it is not possible in HP-UX.

also the lvcextend command shall require the Target Size to specified in MB and extendfs will require the RAW Device file for the LV that is /dev/vg02/rlvol2.

with fsadm that we use in conjunction to OnlineJFS with the -b option we specify as an standard target FS size in KiloBytes , make a notice of the same.

[Anjaneyulu]

Hi,

Can I know the command for create lv by using different pv's

[Eric SAUBIGNAC]

>>>>> Can I know the command for create lv by using different pv's <<<<<

Do you mean that you want to distribute your LV over several PV ?

If yes, create you LV with option -i and -I

-i Set the number of disks to stripe across. stripes must be at least 2.

-I Set the size in kilobytes of the stripe. stripe_size should be a power of 2. stripe_size must be at least 4

For example : "lvcreate -n lvol1 -i 4 -I 64 -L 1024 vgtagada" will create a logical volume of 1 Go, stripped over 4 disk with a 64Ko strip size

Eric

[Ganesan R]

Hi Anjaneyulu,

It is really hard to understand your question. You please always elaborate your question so that we can help you in a better way.

You cannot specify a PV with lvcreate. If you like to place the LV on a specific PV, then first create an LV of 0MB. It has no extents - it just exists.
# lvcreate -n lvdata vg01
Now extend the LV onto a certain disk:
# lvextend -L 500 /dev/vg01/lvdata /dev/dsk/c4t2d0