vgcreate 11.23 vs 11.31

[unix55]

Hi,

i know the below steps when i need to create volume group on HP-UX 11.11 and 11.23

# pvcreate -f /dev/rdsk/cxtxdx

# mkdir /dev/vgxx
# ll /dev/vg*/group
# mknod /dev/vgxx/group c 64 0x**0000
# vgcreate -s 64 /dev/vgxx /dev/dsk/cxtxdx

now what is deference when i need to create volume group v 2.x on 11.31 version.

Thanks

[Matti_Kurkela]

Note: in 11.31, you should use /dev/disk/disk* devices instead of legacy /dev/dsk/c*t*d*, since the legacy syntax is likely to be removed in future HP-UX versions.

For LVM v2.x VGs, the major device number in the mknod command must be 128, not 64.The syntax of the minor number is also different: it's 0x***000, not 0x**0000.

You must add an option to vgcreate to specify the VG version required, i.e. "-V 2.0" or "-V 2.1".

You must also specify the maximum future size to which your VG can grow: for example, if you're sure your VG won't be required to grow to larger than 2 terabytes, the vgcreate step could be:

vgcreate -V 2.1 -s 64 -S 2t /dev/vgxx /dev/disk/diskxx

So:

# pvcreate -f /dev/rdisk/diskNN

# mkdir /dev/vgXX

# ll /dev/vg*/group

# mknod /dev/vgXX/group c 128 0x***000

# vgcreate -V 2.1 -s 64 -S 2t /dev/vgXX /dev/disk/diskNN

If you don't care about the VG minor number, then the mkdir/mknod steps are *optional* in LVM 2.x: if you don't create the VG directory and the group device node, the vgcreate command will automatically pick an unique minor number and create the directory and device node for you automatically. But if you need to select a specific device number (e.g. if you're adding a node to a Serviceguard cluster and must match the VG numbers with the existing nodes) then you can choose the numbers yourself using the procedure as above.