Error creating VG

[Ra Jose]

Is there any limit on the minor number for /dev/VG/group file. On my rp7420 server running 11iv1, I had 42 VGs, last VG showing
minor # as 0x440000. I needed to create a new VG and want to use 0x750000 number for my /dev/vg75/group file. I created this and used mknod to create device group file. Then I did - vgcreate /dev/vg75 /dev/dsk/c#t#d#
This gave me error stating it could not open group file although it was exisitng with
crw-r--r-- permission and root:sys ownership. I tried with minor # 0x550000, it worked. I am not sure whether there is a limit on minor number that can be used.

Thank you all for replies.
Rajos

[A. Clay Stephenson · Accepted solution]

The absolute limit for the 1st two hexadecimal digits on the minor device number is 0xFF (255) but you also cannot exceed the kernel tunable maxvgs. I suspect that your real problem is that you are using hexadecimal when you then you are using decimal values. For example, vg75 should, by convention, be using using 0x4B0000 rather than 0x750000.

[A. Clay Stephenson]

Ooops, I'm an idiot. This sentence (more or less):

I suspect that your real problem is that you are using hexadecimal when you then you are using decimal values.

should read:

I suspect that your real problem is that you are using decimal values when you should be using hexadecimal values.

[Ra Jose]

Thank you Clay. The maxvgs solved my problem. Thx for pointing out this kernel parameter maxvgs which was set to 100 (decimal). So 0x75 would exceed it whereas )x50 would not. BTW, my vg was not vg75 but vgCBACK. I gave a descriptive name to this VG. But this does not seem to be a problem.

Rajos.