unable to create a logical volume although space exists

[John_912]

Dear all,
I am facing the following problem, any help will be highly appreciated:
I try to create a logical volume to my volume group but I got the error:
root# lvcreate -L 2048 -i 12 -I 4 -n lvol1 vg1
Warning: rounding up logical volume size to extent boundary at size "2064" MB for striping.
Logical volume "/dev/vgdb/lvol1" has been successfully created with
character device "/dev/vgdb/rlvol1".
lvcreate: Not enough free physical extents available.
Logical volume "/dev/vgdb/lvol1" could not be extended.
lvcreate: Couldn't retrieve the list of the physical volumes
belonging to volume group "/dev/vg1".
Run the "lvextend" command to create space on the Logical Volume.
But in the attached output of vgdisplay you will see that I have 22968 free PE available.
Also lvextend command fails.
Do you have any ideas?
Thank,
John

[Robert-Jan Goossens]

Hi John,

You do not have free space on all the disks.

-i 12 --> stripes on 12 disks.

Regards,
Robert-Jan

[John_912]

Hello,
Thank you.
So by using for stripes only the disks that I have space then it will be ok?
Could you provide me any suggestions?
Thank you in advance.
John

[Govinda_1]

hi john,

keep an eye on these threads.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=187706

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=778921

regards,
Govind.

[Robert-Jan Goossens]

John difficult question. I don't know what kind of volume you are creating. If you are creating a large database, performance would be better using striped lvol's (over multiple controllers). If I look at your vgdisplay output you are using one controller and most of the volumes are not striped. If you would setup this lvol using stripes, and you would like to extend this volume in the future you will need free extends on those disks.

More info
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=658555

By the way.
A few of the disks are completly empty (/dev/dsk/c4t0d7 /dev/dsk/c4t1d1 etc)

Regards,
Robert-Jan

[Devender Khatana]

Hi John,
As the size of volume is only 2GB. It is not useful as all 12 Disks are using same controller. It can be Stripped across through 4 or 6 Disks maximum.Otherwise also you can not strip it across these 12 as only 7 of your 12 disks in this VG are having free space.

Another good thing what comes to my mind is that You can define half of your devies with c3t* as the primary path & c4 as the alternate path.

This will also give you a good growth in performance as both of your controllers will start getting used simultaneously.
But you can do this only by removing these disksk from VG and reextending VG to these disks with alternate device file. So this applies only to Disks which are free. Another thing what needs to noticed before doing this is what is the controllers you have defined in your other VGs.

HTH,
Devender