Is there a maximum disk size for LVM physical disks?

[Michael Koch_1]

I am trying to add an alternate link to a volumegroup on an FC60. The LUN is 170 GB (6x36 Gb disks Raid 5).
Creating and accessing the vg works fine, but when I try to add an alternate link (via the other FC controller) I run into a timeout and get the Information that there was noe lvm information found on the pv.

I got a similar configuration (same LUN sizes) running on another box.

Any hints ?


Regards

Michael

[Stefan Farrelly]

These 2x 170GB Luns are identical in every way, right ?

To be sure, lets check if they are indeed the same and can be setup as alternate links. Use the following command on each of the physical device files;

echo 2000?8c+8x | adb /dev/dsk/cXXXXXX

The results of this command on both the /dev/dsk entries should be identical, verifying that they can indeed be setup as alternate links. eg;

echo 2000?8c+8x|adb /dev/dsk/c1t0d0
2000: LVMREC016354 59AA 39D9 0xD7A4 6354 59AA 39D9
0xD7D8
echo 2000?8c+8x|adb /dev/dsk/c2t0d0
2000: LVMREC016354 59AA 39D9 0xD7A4 6354 59AA 39D9
0xD7D8

These are the results from 2 EMC Luns which are setup as alternate links, as you can see the info from the echo | adb command is identical. If yours is too but you still cant add them in as alternate links then you have a problem with your Luns/external disk devices which is where you need to investigate further.

[Wodisch]

Hello Michael,
you did not tell us your HP-UX release...
With HP-UX 10.20 there is a maximum LV size of 128GB
(supported, at least - I know bigger ones working), but
with HP-UX 11.x it is 1TB.
BUT I seem to remember something like a no-of-PEs
limit of 16384 per PV. Taking in account the max-PE-size
of 256MB you should not be reaching that limit so
easily ;-).
I would recommend PE sizes of 64MB or more, though.
HTH,
Wodisch

[MANOJ SRIVASTAVA]

Hi Michael

Since it is already working on the second machine so it looks like not related to OS issue . I think the alternate link is not pointing to the same disk . Check for the time stamp in /dev/dsk for both the device files ( to give you a clue ) whether you are accesing the same device in the alternate link .


Manoj Srivastava