topic Re: mknod problem in Operating System - HP-UX

mknod problem

Vincent_5 — Thu, 29 Jul 2004 08:29:55 GMT

Hi ,
Can anyone help, I have a K460 install with HP Unix 10.20 attach with a HASS. There is 4 x 18GB harddisk on the HASS. I'm trying to create new vg on the 4 x 18GB with sam or command line. I get error message mknod"arg count usage" mknod_name b | | c major minor mknod name p . What this this error mean??

Please advice??

Regards
Vincent

Re: mknod problem

David Child_1 — Thu, 29 Jul 2004 08:40:21 GMT

To help answer could you please post the command you ran.

Thanks,
David

Re: mknod problem

Geoff Wild — Thu, 29 Jul 2004 08:40:28 GMT

What was the exact command you used?

Did you have a space after "c"

mknod /dev/vg52/group c 64 0x4c0000

Rgds...Geoff

Re: mknod problem

Chris Wilshaw — Thu, 29 Jul 2004 08:42:03 GMT

can you show us the mknod command that you're trying to run?

for a volume group it should be

cd /dev/vgXX
mknod group c 64 0x0N0000

where XX is the volume group number, and N is a unique hex value.

Re: mknod problem

Fred Ruffet — Thu, 29 Jul 2004 08:42:29 GMT

When creating a vg on HP-UX you must first create the vgstructure manually.
mkdir /dev/vg_name
mknod /dev/vg_name/group c 64 0x..0000
where vg_name is replaced by the name of the vg you plan to create and .. in 0x..000 is 2 digit number identifying the VG. This number must be uniq for all /dev/vgXXX/group files.

It seems that the SAM running on your server is not making a good mknod command. Maybe you are trying to give your vg a bad name...

Regards,

Fred

Re: mknod problem

Jose Mosquera — Thu, 29 Jul 2004 08:46:59 GMT

Hi,

#pvcreate -f /dev/rdsk/cxtyd0
#pvcreate -f /dev/rdsk/cxtyd1
#pvcreate -f /dev/rdsk/cxtyd2
#pvcreate -f /dev/rdsk/cxtyd3
#mkdir -p /dev/vg04
where: vg04 must be unique
#mknod /dev/vg04/group c 64 0x040000
where: minor number 0x040000 must be unique
#vgcreate vg04 /dev/dsk/cxtyd0 /dev/dsk/cxtyd1 /dev/dsk/cxtyd2 /dev/dsk/cxtyd3

Rgds.

Re: mknod problem

Cheryl Griffin — Thu, 29 Jul 2004 08:52:13 GMT

You definitely need to verify your command.

Use lsdev to determine the major number of the device drivers installed.

Your command syntax is incorrect.

Post your command here and we can advise you further.

Re: mknod problem

Cheryl Griffin — Thu, 29 Jul 2004 09:14:20 GMT

Hein - replies deleted.

Re: mknod problem

Jan Sladky — Thu, 29 Jul 2004 09:46:15 GMT

hi Vincent,
steps for creation of VG are following

pvcreate /dev/rdsk/c0tXd0 - PV creation
mkdir /dev/vg01 - vg dir
mknod /dev/vg01/group c 64 0x010000 - VG
control file
c - character device
64- major# for LVM allways
64,info from lsdev
01- vg number in hex
0000 - allways this
vgcreate vg01 /dev/dsk/c0t8d0 dev/dsk/c0t11d0
- vg creation

lvcreate -L 3000 vg01 - lv creation
newfs -F vxfs /dev/vg01/rlvol1 - fs creation
mkfs -m /dev/vg01/lvol1 - fs checking

try it and post results

br Jan

Re: mknod problem

Gary L. Paveza, Jr. — Thu, 29 Jul 2004 09:46:45 GMT

Sounds like you exceeded the value of maxvgs in your kernel. That parameter is a bit strange in that it is not the maximum number of volume groups you can have, but rather the maximum value of the minor number for the mknod command. In your example, you used 4c - which equates to 76 decimal. So your maxvgs value has to be at least 76.

Re: mknod problem

Gary L. Paveza, Jr. — Thu, 29 Jul 2004 09:48:14 GMT

Oops, it wasn't you that posted that example. Anyway, the basic idea is still valid. Check the minor number you used and make sure that the maxvgs kernel parameter is at least equal to it (mknod uses hex - make sure you convert to decimal to compare to kernel).