Ovirt devel - Aug 2009 - RFC - Design of new MPATH device menu in o-c-storage

I am designing a new menu to allow a user to select an mpath device for
installation without having to drop down to the shell to do setup.  A patch to
ovirt-node-image has already been posted to enable multipathd by default.  The
new menu will appear as an option under the normal o-c-storage menu.  Not that a
few of the open design questions are marked in ??

comments are appreciated

Work flow for mpath setup

o-c-setup menu (choose 1 for storage)

Add new option to o-c-storage menu - "Multipath device" that will
spawn the new submenu

Multipath Device Submenu
Display:

List of all Block devices for user to selectively choose 
? Should options be toggles, i.e. choose once to enable, choose again to disable
?
? do we need some way to show whether device is chosen or not (Yes if ^^, no
otherwise ?

Stay on this menu until either "All" or "Finished" is chosen

Other Options
Finished - proceed from this menu - fall back to Multipath device menu if no
devices chosen
Abort - go back to previous menu
blank - same menu redisplayed
All - Add all devices


**Background action**
Based on input, blacklist all but the devices chosen in multipath.conf
restart multipathd service


**New Menu**
Display:

List of mpath devices with similar format to o-c-storage main menu

Other options
Abort option to cancel multipath config and return to main menu
    ?? should abort cleanup multipath.conf setup ? 
blank input - redisplay menu

Choose mpath device -> go to standard partition questions

Mike Burns wrote:
> I am designing a new menu to allow a user to select an mpath device for
installation without having to drop down to the shell to do setup.  A patch to
ovirt-node-image has already been posted to enable multipathd by default.  The
new menu will appear as an option under the normal o-c-storage menu.  Not that a
few of the open design questions are marked in ??
>
> comments are appreciated
>
> Work flow for mpath setup
>
> o-c-setup menu (choose 1 for storage)
>
> Add new option to o-c-storage menu - "Multipath device" that will
spawn the new submenu
>
> Multipath Device Submenu
> Display:
>
> List of all Block devices for user to selectively choose 
> ? Should options be toggles, i.e. choose once to enable, choose again to
disable ?
> ? do we need some way to show whether device is chosen or not (Yes if ^^,
no otherwise ?
>
> Stay on this menu until either "All" or "Finished" is
chosen
>
> Other Options
> Finished - proceed from this menu - fall back to Multipath device menu if
no devices chosen
> Abort - go back to previous menu
> blank - same menu redisplayed
> All - Add all devices
>
>
> **Background action**
> Based on input, blacklist all but the devices chosen in multipath.conf
> restart multipathd service
>
>
> **New Menu**
> Display:
>
> List of mpath devices with similar format to o-c-storage main menu
>
> Other options
> Abort option to cancel multipath config and return to main menu
>     ?? should abort cleanup multipath.conf setup ? 
> blank input - redisplay menu
>
> Choose mpath device -> go to standard partition questions
>
> _______________________________________________
> Ovirt-devel mailing list
> Ovirt-devel at redhat.com
> https://www.redhat.com/mailman/listinfo/ovirt-devel
>   
Sounds pretty good, is there maybe a way to build the luns into some 
kind of display for the user to see like how multipath -ll does without 
configuring itself, othewise the user will definitely need to know what 
each of the luns are.

Rather than (like o-c-storage)
/dev/sda $SIZE $DESCRIPTION
/dev/sdb $SIZE $DESCRIPTION
/dev/sdc $SIZE $DESCRIPTION
/dev/sdd $SIZE $DESCRIPTION


to
mpath0
\ /dev/sda $SIZE $DESCRIPTION
\ /dev/sdb $SIZE $DESCRIPTION

mpath1
\ /dev/sdc $SIZE $DESCRIPTION
\ /dev/sdd $SIZE $DESCRIPTION