Can't extend a LV (free PE's in VG available on both disks)

[dark-sun]

Hello,

for me I have a little bit strange problem.

In the VG I have free extends, on both disks (PVG-strict).

# lvextend -l 440 /dev/vgilnk/lvdata01
lvextend: Not enough free physical extents available.
Logical volume "/dev/vgilnk/lvdata01" could not be extended.

(PS: I'm not shure if I have to use 440 or 880 as new extend count, both did not work)

# vgdisplay -v /dev/vgilnk
--- Volume groups ---
VG Name                     /dev/vgilnk
VG Write Access             read/write
VG Status                   available, exclusive
Max LV                      255
Cur LV                      6
Open LV                     6
Max PV                      48
Cur PV                      2
Act PV                      2
Max PE per PV               8000
VGDA                        4
PE Size (Mbytes)            64
Total PE                    2398
Alloc PE                    1770
Free PE                     628
Total PVG                   0
Total Spare PVs             0
Total Spare PVs in use      0

   --- Logical volumes ---
   LV Name                     /dev/vgilnk/lvdata01
   LV Status                   available/syncd
   LV Size (Mbytes)            25024
   Current LE                  391
   Allocated PE                782
   Used PV                     2
...

...

   --- Physical volumes ---
   PV Name                     /dev/dsk/c64t1d0
   PV Name                     /dev/dsk/c66t1d0 Alternate Link
   PV Name                     /dev/dsk/c72t1d0 Alternate Link
   PV Name                     /dev/dsk/c74t1d0 Alternate Link
   PV Status                   available
   Total PE                    1199
   Free PE                     314
   Autoswitch                  On
   Proactive Polling           Off

   PV Name                     /dev/dsk/c68t1d0
   PV Name                     /dev/dsk/c70t1d0 Alternate Link
   PV Name                     /dev/dsk/c76t1d0 Alternate Link
   PV Name                     /dev/dsk/c78t1d0 Alternate Link
   PV Status                   available
   Total PE                    1199
   Free PE                     314
   Autoswitch                  On
   Proactive Polling           Off

# lvdisplay -v /dev/vgilnk/lvdata01
--- Logical volumes ---
LV Name                     /dev/vgilnk/lvdata01
VG Name                     /dev/vgilnk
LV Permission               read/write
LV Status                   available/syncd
Mirror copies               1
Consistency Recovery        MWC
Schedule                    parallel
LV Size (Mbytes)            25024
Current LE                  391
Allocated PE                782
Stripes                     0
Stripe Size (Kbytes)        0
Bad block                   NONE
Allocation                  PVG-strict
IO Timeout (Seconds)        default

   --- Distribution of logical volume ---
   PV Name            LE on PV  PE on PV
   /dev/dsk/c64t1d0   391       391
   /dev/dsk/c68t1d0   391       391

   --- Logical extents ---
   LE    PV1                PE1   Status 1 PV2                PE2   Status 2
   00000 /dev/dsk/c64t1d0   00000 current  /dev/dsk/c68t1d0   00000 current
   00001 /dev/dsk/c64t1d0   00001 current  /dev/dsk/c68t1d0   00001 current
...

...

Whats wrong?

Is there a limitation of max PE for a LV ?

Thanks,

martin

[Vijaya Ragavan_1]

Hi

          You have available Free PE is 314 on each disk. as your lv is mirrored you can not have 440 PE in VG.

You can extend you lv up to 314 PE

[P Arumugavel]

Hi Martin,

Try with # lvextend -l 314 /dev/vgilnk/lvdata01.

Hope vglink has two PVG and each PVG has one disk.

As Vijay mentioned, your disk hasn't enough free PE, you can't have the space as you given in your caommand.

Hope it makes you understand.

Rgds...

[Torsten.]

If you want to extend to 440 LEs, the LVOL will use 2*440 PEs since the LVOL is mirrored.

[dark-sun]

Hello,
old LV size is 391PE, I have 314 PE free on both disks.
I I want to extend to 440PE, so I need only 49 "new" additionally PE.
Or not?

In # lvextend I have to enter the new target size, not the amount I will increase, or?

Or have a big missunderstanding here?

[Torsten.]

You have only 2 disks, so a PVG doesn't make so much sense. However, check what is inside /etc/lvmpvg!

[Torsten.]

You have only 2 disks, so a PVG doesn't make so much sense.

However, check what is inside /etc/lvmpvg!

[Michael Steele_2]

From your vgdisplay output you have 8 HBA's on this box?  That's great I/O performance but rarely seen.  But note that an alternate link is not a mirror but an alternate path to the same disk.  Also note that four is the industry standard but there is no reason not to have 8 except for the expense of the box and criticality of the data.

This must be a critical box.

From your lvdisplay you have 1 mirrored copy.  That's one primary and one alternate.

This is definitely not the output of a distributed configuration, as Thorsten is pointing out.

All I see here is what has already been stated, 628 free PE / 2 or 314 in vgdisplay and a PVG-Strict being used where Strict-Allocation is called for.

See the vgchange command and investigate this change.  You may have to create a new VG in order to fix this.

[Michael Steele_2]

Thorsten:

"...There are only 10 types of people in the world -..."

ROFLOL - That is hilarious!!!!

[Torsten.]

---

@Michael Steele_2 wrote:

From your vgdisplay output you have 8 HBA's on this box?

---

You cannot say this for sure.

If you have for example a server with 2 FC HBAs and an array with 4 ports per controller (like the larger EVAs) the vgdisplay will exactly look like this.

As asked before, how does the lvmpvg file looks like?

[dark-sun]

---

@Michael Steele_2 wrote:

All I see here is what has already been stated, 628 free PE / 2 or 314 in vgdisplay and a PVG-Strict being used where Strict-Allocation is called for.

See the vgchange command and investigate this change.  You may have to create a new VG in order to fix this.

---

Don't understand this:

Do you mean actuall it's not possible to extend the LV although the VG has free PE on both PV ?

Is there a bug or a missconfiguration from our side? Or any limitation?

Creating a new LV will need a downtime :-(

Thanks!

[dark-sun]

Update:
Just made a test:
Creation of a new LV and extend is possible.

But when I change the new LV: # lvchange -s g ...  (this will set PVG-strict, dont know why this was used before) and try than to extend  >= The same error!

Must these PVG anywhere definded?

I saw:

# ll /etc/lvmpvg
-rw-------   1 root       sys              0 May  8 12:41 /etc/lvmpvg

Thanks!

[dark-sun · Accepted solution]

changed from PVG-strict to strict, than lvextend works!