Too many links

[Joe415]

Hi all,

I have 20 50GB disk with 20 alternates. When I extend the disk to the volume group after the 16th disk I received the erro "vgextend: couldn't install the physical volume too many links". Does anyone know why this happened?

Thanks,
Joe

[Torsten. · Accepted solution]

You hit the limits (MAX_PV).

review man vgcreate

"...
-p max_pv Set the maximum number of physical volumes that the volume group is allowed to contain. The default value for max_pv is 16. The maximum number of physical volumes can be a value in the range 1 to 255."

What version do you run?
(uname -a)

[James R. Ferguson]

Hi Joe:

LVM supports a maximum of eight (8) paths to one physical disk.

Regards!

...JRF...

[Torsten.]

To clarify this:

Alternates are not (yet) the problem.

I guess you are about to extend the disk now.

Try this:

# vgdisplay
--- Volume groups ---
VG Name /dev/vg00
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 10
Open LV 10
Max PV 16


Here you can see the default maximum (16 disks).

You can either start over and delete/create the VG again and set a higher limit or (if you are on 11.23 or 11.31) you can use vgmodify to adjust this.

[James R. Ferguson]

Hi (again):

Yes, upon reading more carefully I agree with Torsten that your alternate links are not (yet) a problem.

If you have just created the volume group, simply destroy it and re-created it specifying a larger value for '-p pv_max' during the 'vgcreate'. If you have data within the volume group and are running 11.31, use 'vgmodify' to increase the 'pv_max'. If you are running 11.23, to enable 'vgmodify' you need PHCO_36744 together with PHKL_31500 and PHKL_32095.

Regards!

...JRF...