Disable - PVG-Strict or Distributed allocation policies.

[Jagadesh_2]

When i try to extend the LV size i am getting the following error

#lvextend -l 52000 /dev/vg02/lvol1
lvextend: Not enough free physical extents available.
Logical volume "/dev/vg02/lvol1" could not be extended.
Failure possibly caused by PVG-Strict or Distributed allocation policies

vgisplay vg02
******************
# vgdisplay vg02
--- Volume groups ---
VG Name /dev/vg02
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 6
Open LV 6
Max PV 255
Cur PV 15
Act PV 15
Max PE per PV 3473
VGDA 30
PE Size (Mbytes) 8
Total PE 52065
Alloc PE 51532
Free PE 533
Total PVG 1
Total Spare PVs 0
Total Spare PVs in use 0

Do i need to disable the PVG-Strict or Distributed allocation policies? If so how can i do the same. I need to do it online.
Online JFS is installed
OS HPUX 11i

Thanks
S.Jagadesh

[RAC_1]

If you do not want to disable PVG strict policy, then you need to add same no. of disks that are in the VG. Else disable the policy, add disk (if enough space is not there) and extend.

[Jagadesh_2]

Enough space is available but when i try to extend i am getting the error.

PE Size (Mbytes) 8
Free PE 533

[Patrick Wallek]

Without seeing how this LV is set up, it's impossible to say exactly what you need to do.

If you could attach the 'lvdisplay -v /dev/vg02/lvol1' output, or post the part up to where it starts mapping PE's to disks, that would help immensely.

If you do want to turn off PVG strict or Distributed allocaiton policy, that can be done with the lvchange command.

[Jagadesh_2]

Pls find the o/p of lvdisplay -v /dev/vg02/lvol1

# lvdisplay -v /dev/vg02/lvol1|more
--- Logical volumes ---
LV Name /dev/vg02/lvol1
VG Name /dev/vg02
LV Permission read/write
LV Status available/syncd
Mirror copies 0
Consistency Recovery MWC
Schedule parallel
LV Size (Mbytes) 67584
Current LE 8448
Allocated PE 8448
Stripes 0
Stripe Size (Kbytes) 0
Bad block on
Allocation PVG-strict/distributed
IO Timeout (Seconds) default

--- Distribution of logical volume ---
PV Name LE on PV PE on PV
/dev/dsk/c11t0d0 639 639
/dev/dsk/c3t0d1 639 639
/dev/dsk/c11t0d2 639 639
/dev/dsk/c3t0d3 638 638
/dev/dsk/c11t0d4 638 638
/dev/dsk/c3t0d5 638 638
/dev/dsk/c11t0d6 638 638
/dev/dsk/c3t0d7 638 638
/dev/dsk/c11t1d0 638 638
/dev/dsk/c3t1d1 638 638
/dev/dsk/c11t1d2 638 638
/dev/dsk/c3t1d3 638 638
/dev/dsk/c11t1d4 637 637
/dev/dsk/c33t3d2 76 76
/dev/dsk/c33t3d3 76 76
............................................................

[Patrick Wallek · Accepted solution]

OK, you do have PVG-Strict and Distributed striping turned on. That means that in order for your lvextend to work you are going to need an EQUAL number of available extents across ALL disks that comprise that particular LV.

Now also keep in mind that you are trying to extend an LV that currently has 8448 extents allocated to it to 52,000 extents across 15 disks.

That means that you need 2,904 extents available on EACH disk that comprises that LV for a total of 43,552 additional extents.

[Jagadesh_2]

How to turn off PVG strict or Distributed allocaiton policy?

Can i turn off the policy online? Let me know the syntax for the same.

[Patrick Wallek]

To turn off the Distributed allocation policy:

# lvchange -D n /dev/vg02/lvol1

That can be done online. After that you should be able to do your lvextend.

[Jagadesh_2]

Thanks Patrick.

Can i enable the policy later after extending the LV?

#lvchange -D y /dev/vg02/lvol1

[Patrick Wallek]

Once you turn it off, I wouldn't turn it back on. That would defeat the purpose of it.