Exporting and Importing volume group..

[boje]

Hi!

I am importing a volume group from another system. But i have a question. When i should use this command: "mknod /dev/vg_ops/group c 64 0xhh0000" How do i know which numer to use? Is there any way to list the taken numbers used on the other volume groups?

Br
Patrik

[Pete Randall · Accepted solution]

Patrik,

Use "ll /dev/vg*/group" to see the existing minor number (the hh in your example). Generally the minor number corresponds to the number of the VG: 00 for vg00, 01 for vg01, etc. In this case you just need to make sure it is unique.


Pete

[SKR_1]

ll /dev/vg*/group

Use different number 0x------

Thanks

SKR

[Prashanth Waugh]

Hi Boje,

if u r using cluster then minor no for that particular vg be same across the node.

Suppose ur importing vg01 on secondary node.
on primary node
ll /dev/vg01/group
use the same minor no on secondary node
vgexport -v -s -p -m /tmp/vg01.map /dev/vg01
on secondary node
vgexport /dev/vg01
mkdir /dev/vg01
ll /dev/vg01
mknod /dev/vg01/group c 64 0x220000
vgimport -s -m /tmp/vgp01.map /dev/vg01
=======================================
Pls if u have doubt.Let me know before carrying out any activity

Regards
Prashant

[Rita C Workman]

Boje,

As Pete mentioned you can run that command to see the numbers already in use. You'd have to do this on every box.
And the best thing is to have a method for tracking the numbers used. Remember documentation does count! So you might create yourself a master document to track the minor numbers in use.

Since with MC/SG you want to keep the minor numbers used for vg's the same on all nodes in the cluster.


Rgrds,
Rita

[boje]

Hi!

Thx for all replies.
I will try ls -l /dev/*vg*/group

Is it best to use same number as on the exporting host? These machines are in a 5 host cluster.

Br

[Prashanth Waugh]

Hi Boje,

try to analysis whether the minor no is same for all vgs on all servers using
#ll /dev/vg*/group
if its same .then first node down the minor no for that particular vg. and use the same on differnt node those are able to see that vg.

Regards
Prashant

[Sandeep_Chaudhary]

if u r system is in cluster then it as advisable to use same number.

ll /dev/vg*/group


it will list all Vg with their major and minor number.

suxde900 # ll /dev/vg*/group
crw-r----- 1 root sys 64 0x000000 Feb 13 2004 /dev/vg00/group
cr--r--r-- 1 root sys 64 0x010000 Apr 29 2004 /dev/vg01/group


here 64 is major number for VG and "0x000000" and "0x010000" are minor number used. if u want to create new VG u have to select different minor number as the minor nbumber is unique.

here "0x" is for ASCII. u can change next two charactre.
here u can get more information about major number minor number

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=391490

[boje]

Problem solved with all these excellent replies.

Br
Patrik