topic mknod ?? minor and major? in Operating System - HP-UX

mknod ?? minor and major?

Deanna Tran_1 — Thu, 01 Aug 2002 22:03:47 GMT

when creating the special file...we
use the minor and major number ? how are those number play the role in vgcreate a volume group?
what does 64 means in major number and 0x010000 in minore means?
because i ran into this error when i tried to
do vgcreate
"can't open the control file"..a.nd when i deleted it again..it works...fine...and somehow helps me to explan this?

Re: mknod ?? minor and major?

Michael Tully — Thu, 01 Aug 2002 22:43:28 GMT

Not sure exactly what you mean.

64 is the major number reporesentation for the LVM driver.

# lsdev | grep lvm
64 64 lv lvm

The minor number represents the group file of the volume group being created. If you have used the first 10 minor numbers, i.e. 10 volume groups, there is a kernel parameter for this called 'maxvgs' that must be increased.

Re: mknod ?? minor and major?

T G Manikandan — Fri, 02 Aug 2002 04:56:46 GMT

Hello,

check these docs

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90698/B2355-90698_top.html&con=/hpux/onlinedocs/B2355-90698/00/00/77-con.html&toc=/hpux/onlinedocs/B2355-90698/00/00/77-toc.html&searchterms=minor%7cmajor&queryid=20020801-224806

Re: mknod ?? minor and major?

Pierce Byrne_1 — Fri, 02 Aug 2002 06:16:24 GMT

In simple terms -
The major number 64 lets hpux know its a volume group.
The minor number groups all the logical volumes within a volume group. The 1st two digits in the minor number identify the volume group and the final two the logical volume within the volume group.