F18 partitioning LVM Question....

[Chris Murphy]

On Dec 28, 2012, at 1:39 AM, Ed Greshko <Ed.Greshko at greshko.com> wrote:

> On 12/28/2012 12:31 AM, Chris Murphy wrote:
>> 
>> If you mean you want a single partition consuming the whole disk, all of it in the VG, but to specify LVs that don't use all of the space in the VG, no you can't do that within anaconda. You'd need to do that in a shell first: partition, make it a pv, add it to a VG, then run anaconda. Any mount points you create will by default become LV's using that VG.
> 
> Your last paragraph says it all....  "you can't do that in anaconda".  *Previously*, you could….

It seems more likely that's incidental behavior, than designed behavior. It's an installer. Its job is to install a system.


> 
> From an F17 system ....
> 
> [root at f17dt ~]# pvscan
>  PV /dev/sda3   VG vg_A   lvm2 [196.91 GiB / 28.31 GiB free]
>  PV /dev/sda2   VG vg_B   lvm2 [58.56 GiB / 14.59 GiB free]
>  Total: 2 [255.47 GiB] / in use: 2 [255.47 GiB] / in no VG: 0 [0   ]
> [root at f17dt ~]# lvscan
>  ACTIVE            '/dev/vg_A/lv01' [97.66 GiB] inherit       (/home)
>  ACTIVE            '/dev/vg_A/lv00' [1.97 GiB] inherit         (swap)
>  ACTIVE            '/dev/vg_A/lv02' [68.97 GiB] inherit       (/usr/local)
>  ACTIVE            '/dev/vg_B/lv01' [34.19 GiB] inherit       (/opt)
>  ACTIVE            '/dev/vg_B/lv00' [9.78 GiB] inherit         (/)

> It was easy to create 2 PV's on one disk and then several LV's within the PV.  As you can see, I've got free space on both PV's which can be added to what LV I want online.

I see confusion. Do you realize you effectively have 10 partitions, that we know of, on a single disk? What's the advantage of sda2 and sda3 being separate instead of in a single VG? You're basically increasing your overall system latency by having multiple PV's on a single spindle. In any case, this is the domain of a different application, not an OS installer.


> 
> Can't do the same configuration at install time, with ease, on F18.  So, the question remains, will the same feature be added in the future as existed in F17 and prior releases?

A valid question for the installer to ask the user is how to allocate disk free space: what amount of that space should become a PV/VG. Making assumptions ensures it's going to be wrong a good percent of the time. 

Chris Murphy