On Sat, Sep 05, 2020 at 01:04:17PM +0200, Tomas Dalebjörk wrote: > I thought that LVM was originally a source copy clone from HPUX LVM? > Hence the questions related to VGDA No, that's not correct. The original LVM1 for Linux developed by Heinz Mauelshagen at Sistina was based on the design and command line model of HPUX LVM, but the source was developed from scratch (although it did use the term VGDA and /etc/lvmtab). Even so, that's more than 20 years ago now - today's Linux LVM2 is an entirely new project but retaining much of the CLI design inspiration that was found in the original LVM1. The LVM2 project started in 2001. > so once I have created this pv header informations, what more do I need in order for the lvconvert -s to accept my cow device? > do I have to also create the minor,major device for the logical volume, or will some other os command do that for me? I think you need to familiarise yourself with the internals of today's LVM2 and device-mapper stack (and the wider Linux storage stack, for example the udev service which manages device nodes in /dev). There are no simple recipe book style answers to the questions you are asking - to do things like this that are outside of the current design limits of the software you really need to have that understanding and ability to inspect and configure the various parts of the system. Even then you may find that there is a lot of work required to get the result you want. You could start off by taking a system installed to LVM2 and then use commands like "dmsetup table" and "dmsetup status" (and comparing those to the LVM2 metadata backups in /etc/lvm) to see how the system puts everything together for you. Then you can start to think about making changes to it. Regards, Bryn. _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
